/*
 * Copyright (C) 2020  钟先耀
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
/*    $OpenBSD: ieee80211_input.c,v 1.235 2021/05/17 08:02:20 stsp Exp $    */

/*-
 * Copyright (c) 2001 Atsushi Onoe
 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
 * Copyright (c) 2007-2009 Damien Bergamini
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/endian.h>
#include <sys/errno.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_llc.h>

#if NBPFILTER > 0
#include <net/bpf.h>
#endif

#include <netinet/in.h>
#include <netinet/if_ether.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_priv.h>

mbuf_t ieee80211_input_hwdecrypt(struct ieee80211com *,
                                 struct ieee80211_node *, mbuf_t,
                                 struct ieee80211_rxinfo *rxi);
mbuf_t ieee80211_defrag(struct ieee80211com *, mbuf_t, int);
void    ieee80211_defrag_timeout(void *);
void    ieee80211_input_ba(struct ieee80211com *, mbuf_t,
                           struct ieee80211_node *, int, struct ieee80211_rxinfo *,
                           struct mbuf_list *);
void    ieee80211_input_ba_flush(struct ieee80211com *, struct ieee80211_node *,
                                 struct ieee80211_rx_ba *, struct mbuf_list *);
int	   ieee80211_input_ba_gap_skip(struct ieee80211_rx_ba *);
void    ieee80211_input_ba_gap_timeout(void *arg);
void    ieee80211_ba_move_window(struct ieee80211com *,
                                 struct ieee80211_node *, u_int8_t, u_int16_t, struct mbuf_list *);
void    ieee80211_input_ba_seq(struct ieee80211com *,
                               struct ieee80211_node *, uint8_t, uint16_t, struct mbuf_list *);
mbuf_t ieee80211_align_mbuf(mbuf_t);
void    ieee80211_decap(struct ieee80211com *, mbuf_t,
                        struct ieee80211_node *, int, struct mbuf_list *);
int    ieee80211_amsdu_decap_validate(struct ieee80211com *, mbuf_t,
                                      struct ieee80211_node *);
void    ieee80211_amsdu_decap(struct ieee80211com *, mbuf_t,
                              struct ieee80211_node *, int, struct mbuf_list *);
void    ieee80211_enqueue_data(struct ieee80211com *, mbuf_t*,
                               struct ieee80211_node *, int, struct mbuf_list *);
int    ieee80211_parse_edca_params_body(struct ieee80211com *,
                                        const u_int8_t *);
int    ieee80211_parse_edca_params(struct ieee80211com *, const u_int8_t *);
int    ieee80211_parse_wmm_params(struct ieee80211com *, const u_int8_t *);
enum    ieee80211_cipher ieee80211_parse_rsn_cipher(const u_int8_t[]);
enum    ieee80211_akm ieee80211_parse_rsn_akm(const u_int8_t[]);
int    ieee80211_parse_rsn_body(struct ieee80211com *, const u_int8_t *,
                                u_int, struct ieee80211_rsnparams *);
int    ieee80211_save_ie(const u_int8_t *, u_int8_t **);
void    ieee80211_recv_probe_resp(struct ieee80211com *, mbuf_t,
                                  struct ieee80211_node *, struct ieee80211_rxinfo *, int);
#ifndef IEEE80211_STA_ONLY
void    ieee80211_recv_probe_req(struct ieee80211com *, mbuf_t,
                                 struct ieee80211_node *, struct ieee80211_rxinfo *);
#endif
void    ieee80211_recv_auth(struct ieee80211com *, mbuf_t,
                            struct ieee80211_node *, struct ieee80211_rxinfo *);
#ifndef IEEE80211_STA_ONLY
void    ieee80211_recv_assoc_req(struct ieee80211com *, mbuf_t,
                                 struct ieee80211_node *, struct ieee80211_rxinfo *, int);
#endif
void    ieee80211_recv_assoc_resp(struct ieee80211com *, mbuf_t,
                                  struct ieee80211_node *, int);
void    ieee80211_recv_deauth(struct ieee80211com *, mbuf_t,
                              struct ieee80211_node *);
void    ieee80211_recv_disassoc(struct ieee80211com *, mbuf_t,
                                struct ieee80211_node *);
void    ieee80211_recv_addba_req(struct ieee80211com *, mbuf_t,
                                 struct ieee80211_node *);
void    ieee80211_recv_addba_resp(struct ieee80211com *, mbuf_t,
                                  struct ieee80211_node *);
void    ieee80211_recv_delba(struct ieee80211com *, mbuf_t,
                             struct ieee80211_node *);
void    ieee80211_recv_sa_query_req(struct ieee80211com *, mbuf_t,
                                    struct ieee80211_node *);
#ifndef IEEE80211_STA_ONLY
void    ieee80211_recv_sa_query_resp(struct ieee80211com *, mbuf_t,
                                     struct ieee80211_node *);
#endif
void    ieee80211_recv_action(struct ieee80211com *, mbuf_t,
                              struct ieee80211_node *);
#ifndef IEEE80211_STA_ONLY
void    ieee80211_recv_pspoll(struct ieee80211com *, mbuf_t,
                              struct ieee80211_node *);
#endif
void    ieee80211_recv_bar(struct ieee80211com *, mbuf_t,
                           struct ieee80211_node *);
void    ieee80211_bar_tid(struct ieee80211com *, struct ieee80211_node *,
                          u_int8_t, u_int16_t);


/*
 * Retrieve the length in bytes of an 802.11 header.
 */
u_int
ieee80211_get_hdrlen(const struct ieee80211_frame *wh)
{
    u_int size = sizeof(*wh);
    
    /* NB: does not work with control frames */
    _KASSERT(ieee80211_has_seq(wh));
    
    if (ieee80211_has_addr4(wh))
        size += IEEE80211_ADDR_LEN;    /* i_addr4 */
    if (ieee80211_has_qos(wh))
        size += sizeof(u_int16_t);    /* i_qos */
    if (ieee80211_has_htc(wh))
        size += sizeof(u_int32_t);    /* i_ht */
    return size;
}

/* Post-processing for drivers which perform decryption in hardware. */
mbuf_t
ieee80211_input_hwdecrypt(struct ieee80211com *ic, struct ieee80211_node *ni,
    mbuf_t m, struct ieee80211_rxinfo *rxi)
{
   struct ieee80211_key *k;
   struct ieee80211_frame *wh;
   uint64_t pn, *prsc;
   int hdrlen;

   k = ieee80211_get_rxkey(ic, m, ni);
   if (k == NULL)
       return NULL;

   wh = mtod(m, struct ieee80211_frame *);
   hdrlen = ieee80211_get_hdrlen(wh);

   /*
    * Update the last-seen packet number (PN) for drivers using hardware
    * crypto offloading. This cannot be done by drivers because A-MPDU
    * reordering needs to occur before a valid lower bound can be
    * determined for the PN. Drivers will read the PN we write here and
    * are expected to discard replayed frames based on it.
    * Drivers are expected to leave the IV of decrypted frames intact
    * so we can update the last-seen PN and strip the IV here.
    */
   switch (k->k_cipher) {
   case IEEE80211_CIPHER_CCMP:
       if (!(wh->i_fc[1] & IEEE80211_FC1_PROTECTED)) {
           /*
            * If the protected bit is clear then hardware has
            * stripped the IV and we must trust that it handles
            * replay detection correctly.
            */
           break;
       }
           if (ieee80211_ccmp_get_pn(&pn, &prsc, m, k) != 0)
               return NULL;
           if (rxi->rxi_flags & IEEE80211_RXI_HWDEC_SAME_PN) {
               if (pn < *prsc) {
                   ic->ic_stats.is_ccmp_replays++;
                   return NULL;
               }
           } else if (pn <= *prsc) {
               ic->ic_stats.is_ccmp_replays++;
               return NULL;
           }

       /* Update last-seen packet number. */
       *prsc = pn;

       /* Clear Protected bit and strip IV. */
       wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
       memmove(mtod(m, caddr_t) + IEEE80211_CCMP_HDRLEN, wh, hdrlen);
       mbuf_adj(m, IEEE80211_CCMP_HDRLEN);
       /* Drivers are expected to strip the MIC. */
       break;
    case IEEE80211_CIPHER_TKIP:
       if (!(wh->i_fc[1] & IEEE80211_FC1_PROTECTED)) {
           /*
            * If the protected bit is clear then hardware has
            * stripped the IV and we must trust that it handles
            * replay detection correctly.
            */
           break;
       }
       if (ieee80211_tkip_get_tsc(&pn, &prsc, m, k) != 0)
           return NULL;

       if (rxi->rxi_flags & IEEE80211_RXI_HWDEC_SAME_PN) {
           if (pn < *prsc) {
               ic->ic_stats.is_tkip_replays++;
               return NULL;
               }
           } else if (pn <= *prsc) {
           ic->ic_stats.is_tkip_replays++;
           return NULL;
       }

       /* Update last-seen packet number. */
       *prsc = pn;

       /* Clear Protected bit and strip IV. */
       wh = mtod(m, struct ieee80211_frame *);
       wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
       memmove(mtod(m, caddr_t) + IEEE80211_TKIP_HDRLEN, wh, hdrlen);
       mbuf_adj(m, IEEE80211_TKIP_HDRLEN);
       /* Drivers are expected to strip the MIC. */
       break;
   default:
       break;
   }

   return m;
}

/*
 * Process a received frame.  The node associated with the sender
 * should be supplied.  If nothing was found in the node table then
 * the caller is assumed to supply a reference to ic_bss instead.
 * The RSSI and a timestamp are also supplied.  The RSSI data is used
 * during AP scanning to select a AP to associate with; it can have
 * any units so long as values have consistent units and higher values
 * mean ``better signal''.  The receive timestamp is currently not used
 * by the 802.11 layer.
 *
 * This function acts on management frames immediately and queues data frames
 * on the specified mbuf list. Delivery of queued data frames to upper layers
 * must be triggered with if_input(). Drivers should call if_input() only once
 * per Rx interrupt to avoid triggering the input ifq pressure drop mechanism
 * unnecessarily.
 */
void
ieee80211_inputm(struct _ifnet *ifp, mbuf_t m, struct ieee80211_node *ni,
                 struct ieee80211_rxinfo *rxi, struct mbuf_list *ml)
{
    struct ieee80211com *ic = (struct ieee80211com *)ifp;
    struct ieee80211_frame *wh;
    u_int16_t *orxseq, nrxseq, qos;
    u_int8_t dir, type, subtype, tid;
    int hdrlen, hasqos;
    
    _KASSERT(ni != NULL);
    
    /* in monitor mode, send everything directly to bpf */
    if (ic->ic_opmode == IEEE80211_M_MONITOR)
        goto out;
    
    /*
     * Do not process frames without an Address 2 field any further.
     * Only CTS and ACK control frames do not have this field.
     */
    if (mbuf_len(m) < sizeof(struct ieee80211_frame_min)) {
        DPRINTF(("frame too short, len %u\n", mbuf_len(m)));
        ic->ic_stats.is_rx_tooshort++;
        goto out;
    }
    
    wh = mtod(m, struct ieee80211_frame *);
    if ((wh->i_fc[0] & IEEE80211_FC0_VERSION_MASK) !=
        IEEE80211_FC0_VERSION_0) {
        DPRINTF(("frame with wrong version: %x\n", wh->i_fc[0]));
        ic->ic_stats.is_rx_badversion++;
        goto err;
    }
    
    dir = wh->i_fc[1] & IEEE80211_FC1_DIR_MASK;
    type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
    subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
    
    if (type != IEEE80211_FC0_TYPE_CTL) {
        hdrlen = ieee80211_get_hdrlen(wh);
        if (mbuf_len(m) < hdrlen) {
            DPRINTF(("frame too short, len %u\n", mbuf_len(m)));
            ic->ic_stats.is_rx_tooshort++;
            goto err;
        }
    } else
        hdrlen = 0;
    if ((hasqos = ieee80211_has_qos(wh))) {
        qos = ieee80211_get_qos(wh);
        tid = qos & IEEE80211_QOS_TID;
    } else {
        qos = 0;
        tid = 0;
    }
    
    if (ic->ic_state == IEEE80211_S_RUN &&
        type == IEEE80211_FC0_TYPE_DATA && hasqos &&
        (subtype & IEEE80211_FC0_SUBTYPE_NODATA) == 0 &&
        !(rxi->rxi_flags & IEEE80211_RXI_AMPDU_DONE)
#ifndef IEEE80211_STA_ONLY
        && (ic->ic_opmode == IEEE80211_M_STA || ni != ic->ic_bss)
#endif
        ) {
        int ba_state = ni->ni_rx_ba[tid].ba_state;
        
#ifndef IEEE80211_STA_ONLY
        if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
            if (!IEEE80211_ADDR_EQ(wh->i_addr1,
                                   ic->ic_bss->ni_bssid)) {
                ic->ic_stats.is_rx_wrongbss++;
                goto err;
            }
            if (ni->ni_state != IEEE80211_S_ASSOC) {
                ic->ic_stats.is_rx_notassoc++;
                goto err;
            }
        }
#endif
        /*
         * If Block Ack was explicitly requested, check
         * if we have a BA agreement for this RA/TID.
         */
        if ((qos & IEEE80211_QOS_ACK_POLICY_MASK) ==
            IEEE80211_QOS_ACK_POLICY_BA &&
            ba_state != IEEE80211_BA_AGREED) {
            DPRINTF(("no BA agreement for %s, TID %d\n",
                     ether_sprintf(ni->ni_macaddr), tid));
            /* send a DELBA with reason code UNKNOWN-BA */
            IEEE80211_SEND_ACTION(ic, ni,
                                  IEEE80211_CATEG_BA, IEEE80211_ACTION_DELBA,
                                  IEEE80211_REASON_SETUP_REQUIRED << 16 | tid);
            goto err;
        }
        
        /*
         * Check if we have an explicit or implicit
         * Block Ack Request for a valid BA agreement.
         */
        if (ba_state == IEEE80211_BA_AGREED &&
            ((qos & IEEE80211_QOS_ACK_POLICY_MASK) ==
             IEEE80211_QOS_ACK_POLICY_BA ||
             (qos & IEEE80211_QOS_ACK_POLICY_MASK) ==
             IEEE80211_QOS_ACK_POLICY_NORMAL)) {
            /* go through A-MPDU reordering */
            ieee80211_input_ba(ic, m, ni, tid, rxi, ml);
            return;    /* don't free m! */
        } else if (ba_state == IEEE80211_BA_REQUESTED &&
            (qos & IEEE80211_QOS_ACK_POLICY_MASK) ==
            IEEE80211_QOS_ACK_POLICY_NORMAL) {
            /*
             * Apparently, qos frames for a tid where a
             * block ack agreement was requested but not
             * yet confirmed by us should still contribute
             * to the sequence number for this tid.
             */
            ieee80211_input_ba(ic, m, ni, tid, rxi, ml);
            return;    /* don't free m! */
        }
    }
    
    /*
     * We do not yet support fragments. Drop any fragmented packets.
     * Counter-measure against attacks where an arbitrary packet is
     * injected via a fragment with attacker-controlled content.
     * See https://papers.mathyvanhoef.com/usenix2021.pdf
     * Section 6.8 "Treating fragments as full frames"
     */
    if (ieee80211_has_seq(wh)) {
        uint16_t rxseq = letoh16(*(const u_int16_t *)wh->i_seq);
        if ((wh->i_fc[1] & IEEE80211_FC1_MORE_FRAG) ||
            (rxseq & IEEE80211_SEQ_FRAG_MASK))
            goto err;
    }
    
    /* duplicate detection (see 9.2.9) */
    if (ieee80211_has_seq(wh) &&
        ic->ic_state != IEEE80211_S_SCAN) {
        nrxseq = letoh16(*(u_int16_t *)wh->i_seq) >>
        IEEE80211_SEQ_SEQ_SHIFT;
        if (hasqos)
            orxseq = &ni->ni_qos_rxseqs[tid];
        else
            orxseq = &ni->ni_rxseq;
        if (rxi->rxi_flags & IEEE80211_RXI_SAME_SEQ) {
            if (nrxseq != *orxseq) {
                /* duplicate, silently discarded */
                ic->ic_stats.is_rx_dup++;
                goto out;
            }
        } else if ((wh->i_fc[1] & IEEE80211_FC1_RETRY) &&
                   nrxseq == *orxseq) {
            /* duplicate, silently discarded */
            ic->ic_stats.is_rx_dup++;
            goto out;
        }
        *orxseq = nrxseq;
    }
    if (ic->ic_state > IEEE80211_S_SCAN) {
        ni->ni_rssi = rxi->rxi_rssi;
        ni->ni_rstamp = rxi->rxi_tstamp;
        ni->ni_inact = 0;
        
        if (ic->ic_state == IEEE80211_S_RUN && ic->ic_bgscan_start) {
            /* Cancel or start background scan based on RSSI. */
            if ((*ic->ic_node_checkrssi)(ic, ni))
                timeout_del(&ic->ic_bgscan_timeout);
            else if (!timeout_pending(&ic->ic_bgscan_timeout) &&
                     (ic->ic_flags & IEEE80211_F_BGSCAN) == 0 &&
                     (ic->ic_flags & IEEE80211_F_DESBSSID) == 0)
                timeout_add_msec(&ic->ic_bgscan_timeout,
                                 500 * (ic->ic_bgscan_fail + 1));
        }
    }
    
#ifndef IEEE80211_STA_ONLY
    if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
        (ic->ic_caps & IEEE80211_C_APPMGT) &&
        ni->ni_state == IEEE80211_STA_ASSOC) {
        if (wh->i_fc[1] & IEEE80211_FC1_PWR_MGT) {
            if (ni->ni_pwrsave == IEEE80211_PS_AWAKE) {
                /* turn on PS mode */
                ni->ni_pwrsave = IEEE80211_PS_DOZE;
                DPRINTF(("PS mode on for %s\n",
                         ether_sprintf(wh->i_addr2)));
            }
        } else if (ni->ni_pwrsave == IEEE80211_PS_DOZE) {
            mbuf_t m;
            
            /* turn off PS mode */
            ni->ni_pwrsave = IEEE80211_PS_AWAKE;
            DPRINTF(("PS mode off for %s\n",
                     ether_sprintf(wh->i_addr2)));
            
            (*ic->ic_set_tim)(ic, ni->ni_associd, 0);
            
            /* dequeue buffered unicast frames */
            while ((m = mq_dequeue(&ni->ni_savedq)) != NULL) {
                mq_enqueue(&ic->ic_pwrsaveq, m);
                ifp->if_start(ifp);
            }
        }
    }
#endif
    switch (type) {
        case IEEE80211_FC0_TYPE_DATA:
            switch (ic->ic_opmode) {
                case IEEE80211_M_STA:
                    if (dir != IEEE80211_FC1_DIR_FROMDS) {
                        ic->ic_stats.is_rx_wrongdir++;
                        goto out;
                    }
                    if (ic->ic_state != IEEE80211_S_SCAN &&
                        !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_bssid)) {
                        /* Source address is not our BSS. */
                        DPRINTF(("discard frame from SA %s\n",
                                 ether_sprintf(wh->i_addr2)));
                        ic->ic_stats.is_rx_wrongbss++;
                        goto out;
                    }
                    if ((ifp->if_flags & IFF_SIMPLEX) &&
                        IEEE80211_IS_MULTICAST(wh->i_addr1) &&
                        IEEE80211_ADDR_EQ(wh->i_addr3, ic->ic_myaddr)) {
                        /*
                         * In IEEE802.11 network, multicast frame
                         * sent from me is broadcasted from AP.
                         * It should be silently discarded for
                         * SIMPLEX interface.
                         */
                        ic->ic_stats.is_rx_mcastecho++;
                        goto out;
                    }
                    break;
#ifndef IEEE80211_STA_ONLY
                case IEEE80211_M_IBSS:
                case IEEE80211_M_AHDEMO:
                    if (dir != IEEE80211_FC1_DIR_NODS) {
                        ic->ic_stats.is_rx_wrongdir++;
                        goto out;
                    }
                    if (ic->ic_state != IEEE80211_S_SCAN &&
                        !IEEE80211_ADDR_EQ(wh->i_addr3,
                                           ic->ic_bss->ni_bssid) &&
                        !IEEE80211_ADDR_EQ(wh->i_addr3,
                                           etherbroadcastaddr)) {
                        /* Destination is not our BSS or broadcast. */
                        DPRINTF(("discard data frame to DA %s\n",
                                 ether_sprintf(wh->i_addr3)));
                        ic->ic_stats.is_rx_wrongbss++;
                        goto out;
                    }
                    break;
                case IEEE80211_M_HOSTAP:
                    if (dir != IEEE80211_FC1_DIR_TODS) {
                        ic->ic_stats.is_rx_wrongdir++;
                        goto out;
                    }
                    if (ic->ic_state != IEEE80211_S_SCAN &&
                        !IEEE80211_ADDR_EQ(wh->i_addr1,
                                           ic->ic_bss->ni_bssid) &&
                        !IEEE80211_ADDR_EQ(wh->i_addr1,
                                           etherbroadcastaddr)) {
                        /* BSS is not us or broadcast. */
                        DPRINTF(("discard data frame to BSS %s\n",
                                 ether_sprintf(wh->i_addr1)));
                        ic->ic_stats.is_rx_wrongbss++;
                        goto out;
                    }
                    /* check if source STA is associated */
                    if (ni == ic->ic_bss) {
                        DPRINTF(("data from unknown src %s\n",
                                 ether_sprintf(wh->i_addr2)));
                        /* NB: caller deals with reference */
                        ni = ieee80211_find_node(ic, wh->i_addr2);
                        if (ni == NULL)
                            ni = ieee80211_dup_bss(ic, wh->i_addr2);
                        if (ni != NULL) {
                            IEEE80211_SEND_MGMT(ic, ni,
                                                IEEE80211_FC0_SUBTYPE_DEAUTH,
                                                IEEE80211_REASON_NOT_AUTHED);
                        }
                        ic->ic_stats.is_rx_notassoc++;
                        goto err;
                    }
                    if (ni->ni_state != IEEE80211_STA_ASSOC) {
                        DPRINTF(("data from unassoc src %s\n",
                                 ether_sprintf(wh->i_addr2)));
                        IEEE80211_SEND_MGMT(ic, ni,
                                            IEEE80211_FC0_SUBTYPE_DISASSOC,
                                            IEEE80211_REASON_NOT_ASSOCED);
                        ic->ic_stats.is_rx_notassoc++;
                        goto err;
                    }
                    break;
#endif    /* IEEE80211_STA_ONLY */
                default:
                    /* can't get there */
                    goto out;
            }
            
            /* Do not process "no data" frames any further. */
            if (subtype & IEEE80211_FC0_SUBTYPE_NODATA) {
#if NBPFILTER > 0
                if (ic->ic_rawbpf)
                    bpf_mtap(ic->ic_rawbpf, m, BPF_DIRECTION_IN);
#endif
                goto out;
            }
            
            if ((ic->ic_flags & IEEE80211_F_WEPON) ||
                ((ic->ic_flags & IEEE80211_F_RSNON) &&
                 (ni->ni_flags & IEEE80211_NODE_RXPROT))) {
                /* protection is on for Rx */
                if (!(rxi->rxi_flags & IEEE80211_RXI_HWDEC)) {
                    if (!(wh->i_fc[1] & IEEE80211_FC1_PROTECTED)) {
                        /* drop unencrypted */
                        ic->ic_stats.is_rx_unencrypted++;
                        goto err;
                    }
                    /* do software decryption */
                    m = ieee80211_decrypt(ic, m, ni);
                    if (m == NULL) {
                        ic->ic_stats.is_rx_wepfail++;
                        goto err;
                    }
                } else {
                    m = ieee80211_input_hwdecrypt(ic, ni, m, rxi);
                    if (m == NULL)
                        goto err;
                }
                wh = mtod(m, struct ieee80211_frame *);
            } else if ((wh->i_fc[1] & IEEE80211_FC1_PROTECTED) ||
                       (rxi->rxi_flags & IEEE80211_RXI_HWDEC)) {
                /* frame encrypted but protection off for Rx */
                ic->ic_stats.is_rx_nowep++;
                goto out;
            }
            
#if NBPFILTER > 0
            /* copy to listener after decrypt */
            if (ic->ic_rawbpf)
                bpf_mtap(ic->ic_rawbpf, m, BPF_DIRECTION_IN);
#endif
            
            if ((ni->ni_flags & IEEE80211_NODE_HT) &&
                hasqos && (qos & IEEE80211_QOS_AMSDU))
                ieee80211_amsdu_decap(ic, m, ni, hdrlen, ml);
            else
                ieee80211_decap(ic, m, ni, hdrlen, ml);
            return;
            
        case IEEE80211_FC0_TYPE_MGT:
            if (dir != IEEE80211_FC1_DIR_NODS) {
                ic->ic_stats.is_rx_wrongdir++;
                goto err;
            }
#ifndef IEEE80211_STA_ONLY
            if (ic->ic_opmode == IEEE80211_M_AHDEMO) {
                ic->ic_stats.is_rx_ahdemo_mgt++;
                goto out;
            }
#endif
            /* drop frames without interest */
            if (ic->ic_state == IEEE80211_S_SCAN) {
                if (subtype != IEEE80211_FC0_SUBTYPE_BEACON &&
                    subtype != IEEE80211_FC0_SUBTYPE_PROBE_RESP) {
                    ic->ic_stats.is_rx_mgtdiscard++;
                    goto out;
                }
            }
            
            if (ni->ni_flags & IEEE80211_NODE_RXMGMTPROT) {
                /* MMPDU protection is on for Rx */
                if (subtype == IEEE80211_FC0_SUBTYPE_DISASSOC ||
                    subtype == IEEE80211_FC0_SUBTYPE_DEAUTH ||
                    subtype == IEEE80211_FC0_SUBTYPE_ACTION) {
                    if (!IEEE80211_IS_MULTICAST(wh->i_addr1) &&
                        !(wh->i_fc[1] & IEEE80211_FC1_PROTECTED)) {
                        /* unicast mgmt not encrypted */
                        goto out;
                    }
                    /* do software decryption */
                    m = ieee80211_decrypt(ic, m, ni);
                    if (m == NULL) {
                        /* XXX stats */
                        goto out;
                    }
                    wh = mtod(m, struct ieee80211_frame *);
                }
            } else if ((ic->ic_flags & IEEE80211_F_RSNON) &&
                       (wh->i_fc[1] & IEEE80211_FC1_PROTECTED)) {
                /* encrypted but MMPDU Rx protection off for TA */
                goto out;
            }
            
#if NBPFILTER > 0
            if (bpf_mtap(ic->ic_rawbpf, m, BPF_DIRECTION_IN) != 0) {
                /*
                 * Drop mbuf if it was filtered by bpf. Normally,
                 * this is done in ether_input() but IEEE 802.11
                 * management frames are a special case.
                 */
                mbuf_freem(m);
                return;
            }
#endif
            (*ic->ic_recv_mgmt)(ic, m, ni, rxi, subtype);
            mbuf_freem(m);
            return;
            
        case IEEE80211_FC0_TYPE_CTL:
            switch (subtype) {
#ifndef IEEE80211_STA_ONLY
                case IEEE80211_FC0_SUBTYPE_PS_POLL:
                    ieee80211_recv_pspoll(ic, m, ni);
                    break;
#endif
                case IEEE80211_FC0_SUBTYPE_BAR:
                    ieee80211_recv_bar(ic, m, ni);
                    break;
                default:
                    ic->ic_stats.is_rx_ctl++;
                    break;
            }
            goto out;
            
        default:
            DPRINTF(("bad frame type %x\n", type));
            /* should not come here */
            break;
    }
err:
    ifp->netStat->inputErrors++;
out:
    if (m != NULL) {
#if NBPFILTER > 0
        if (ic->ic_rawbpf)
            bpf_mtap(ic->ic_rawbpf, m, BPF_DIRECTION_IN);
#endif
        mbuf_freem(m);
    }
}

/* Input handler for drivers which only receive one frame per interrupt. */
void
ieee80211_input(struct _ifnet *ifp, mbuf_t m, struct ieee80211_node *ni,
                struct ieee80211_rxinfo *rxi)
{
    struct mbuf_list ml = MBUF_LIST_INITIALIZER();
    
    ieee80211_inputm(ifp, m, ni, rxi, &ml);
    if_input(ifp, &ml);
}

#ifdef notyet
/*
 * Handle defragmentation (see 9.5 and Annex C).  We support the concurrent
 * reception of fragments of three fragmented MSDUs or MMPDUs.
 */
mbuf_t
ieee80211_defrag(struct ieee80211com *ic, mbuf_t m, int hdrlen)
{
    const struct ieee80211_frame *owh, *wh;
    struct ieee80211_defrag *df;
    u_int16_t rxseq, seq;
    u_int8_t frag;
    int i;
    
    wh = mtod(m, struct ieee80211_frame *);
    rxseq = letoh16(*(const u_int16_t *)wh->i_seq);
    seq = rxseq >> IEEE80211_SEQ_SEQ_SHIFT;
    frag = rxseq & IEEE80211_SEQ_FRAG_MASK;
    
    if (frag == 0 && !(wh->i_fc[1] & IEEE80211_FC1_MORE_FRAG))
        return m;	/* not fragmented */
    
    if (frag == 0) {
        /* first fragment, setup entry in the fragment cache */
        if (++ic->ic_defrag_cur == IEEE80211_DEFRAG_SIZE)
            ic->ic_defrag_cur = 0;
        df = &ic->ic_defrag[ic->ic_defrag_cur];
        mbuf_freem(df->df_m);	/* discard old entry */
        df->df_seq = seq;
        df->df_frag = 0;
        df->df_m = m;
        /* start receive MSDU timer of aMaxReceiveLifetime */
        timeout_add_sec(&df->df_to, 1);
        return NULL;	/* MSDU or MMPDU not yet complete */
    }
    
    /* find matching entry in the fragment cache */
    for (i = 0; i < IEEE80211_DEFRAG_SIZE; i++) {
        df = &ic->ic_defrag[i];
        if (df->df_m == NULL)
            continue;
        if (df->df_seq != seq || df->df_frag + 1 != frag)
            continue;
        owh = mtod(df->df_m, struct ieee80211_frame *);
        /* frame type, source and destination must match */
        if (((wh->i_fc[0] ^ owh->i_fc[0]) & IEEE80211_FC0_TYPE_MASK) ||
            !IEEE80211_ADDR_EQ(wh->i_addr1, owh->i_addr1) ||
            !IEEE80211_ADDR_EQ(wh->i_addr2, owh->i_addr2))
            continue;
        /* matching entry found */
        break;
    }
    if (i == IEEE80211_DEFRAG_SIZE) {
        /* no matching entry found, discard fragment */
        ic->ic_if.netStat->inputErrors++;
        mbuf_freem(m);
        return NULL;
    }
    
    df->df_frag = frag;
    /* strip 802.11 header and concatenate fragment */
    mbuf_adj(m, hdrlen);
    m_cat(df->df_m, m);
    mbuf_pkthdr_setlen(df->df_m, mbuf_pkthdr_len(df->df_m) + mbuf_pkthdr_len(m));
    
    if (wh->i_fc[1] & IEEE80211_FC1_MORE_FRAG)
        return NULL;	/* MSDU or MMPDU not yet complete */
    
    /* MSDU or MMPDU complete */
    timeout_del(&df->df_to);
    m = df->df_m;
    df->df_m = NULL;
    return m;
}

/*
 * Receive MSDU defragmentation timer exceeds aMaxReceiveLifetime.
 */
void
ieee80211_defrag_timeout(void *arg)
{
    struct ieee80211_defrag *df = (struct ieee80211_defrag *)arg;
    int s = splnet();
    
    /* discard all received fragments */
    mbuf_freem(df->df_m);
    df->df_m = NULL;
    
    splx(s);
}
#endif

/*
 * Process a received data MPDU related to a specific HT-immediate Block Ack
 * agreement (see 9.10.7.6).
 */
void
ieee80211_input_ba(struct ieee80211com *ic, mbuf_t m,
                   struct ieee80211_node *ni, int tid, struct ieee80211_rxinfo *rxi,
                   struct mbuf_list *ml)
{
    struct _ifnet *ifp = &ic->ic_if;
    struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid];
    struct ieee80211_frame *wh;
    int idx, count;
    u_int16_t sn;
    
    wh = mtod(m, struct ieee80211_frame *);
    sn = letoh16(*(u_int16_t *)wh->i_seq) >> IEEE80211_SEQ_SEQ_SHIFT;
    
    /* reset Block Ack inactivity timer */
    if (ba->ba_timeout_val != 0)
        timeout_add_usec(&ba->ba_to, ba->ba_timeout_val);
    
    if (SEQ_LT(sn, ba->ba_winstart)) {	/* SN < WinStartB */
        ic->ic_stats.is_ht_rx_frame_below_ba_winstart++;
        mbuf_freem(m);	/* discard the MPDU */
        return;
    }
    if (ba->ba_buf == NULL) {
        XYLog("SEVERE !!!! %s %d ba->ba_buf == NULL\n", __FUNCTION__, __LINE__);
        ifp->netStat->inputErrors++;
        ic->ic_stats.is_ht_rx_ba_no_buf++;
        mbuf_freem(m);
        return;
    }
    if (SEQ_LT(ba->ba_winend, sn)) {	/* WinEndB < SN */
        ic->ic_stats.is_ht_rx_frame_above_ba_winend++;
        count = (sn - ba->ba_winend) & 0xfff;
        if (count > ba->ba_winsize) {
            /*
             * Check whether we're consistently behind the window,
             * and let the window move forward if neccessary.
             */
            if (ba->ba_winmiss < IEEE80211_BA_MAX_WINMISS) {
                if (ba->ba_missedsn == ((sn - 1) & 0xfff))
                    ba->ba_winmiss++;
                else
                    ba->ba_winmiss = 0;
                ba->ba_missedsn = sn;
                ifp->netStat->inputErrors++;
                mbuf_freem(m);	/* discard the MPDU */
                return;
            }
            
            /* It appears the window has moved for real. */
            ic->ic_stats.is_ht_rx_ba_window_jump++;
            ba->ba_winmiss = 0;
            ba->ba_missedsn = 0;
            ieee80211_ba_move_window(ic, ni, tid, sn, ml);
        } else {
            ic->ic_stats.is_ht_rx_ba_window_slide++;
            ieee80211_input_ba_seq(ic, ni, tid,
                                   (ba->ba_winstart + count) & 0xfff, ml);
            ieee80211_input_ba_flush(ic, ni, ba, ml);
        }
    }
    /* WinStartB <= SN <= WinEndB */
    
    ba->ba_winmiss = 0;
    ba->ba_missedsn = 0;
    idx = (sn - ba->ba_winstart) & 0xfff;
    idx = (ba->ba_head + idx) % IEEE80211_BA_MAX_WINSZ;
    /* store the received MPDU in the buffer */
    if (ba->ba_buf[idx].m != NULL) {
        ifp->netStat->inputErrors++;
        ic->ic_stats.is_ht_rx_ba_no_buf++;
        mbuf_freem(m);
        return;
    }
    ba->ba_buf[idx].m = m;
    /* store Rx meta-data too */
    rxi->rxi_flags |= IEEE80211_RXI_AMPDU_DONE;
    ba->ba_buf[idx].rxi = *rxi;
    ba->ba_gapwait++;

    if (ba->ba_buf[ba->ba_head].m == NULL && ba->ba_gapwait == 1)
        timeout_add_msec(&ba->ba_gap_to, IEEE80211_BA_GAP_TIMEOUT);
    
    ieee80211_input_ba_flush(ic, ni, ba, ml);
}

/* 
 * Forward buffered frames with sequence number lower than max_seq.
 * See 802.11-2012 9.21.7.6.2 b.
 */
void
ieee80211_input_ba_seq(struct ieee80211com *ic, struct ieee80211_node *ni,
                       uint8_t tid, uint16_t max_seq, struct mbuf_list *ml)
{
    struct _ifnet *ifp = &ic->ic_if;
    struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid];
    struct ieee80211_frame *wh;
    uint16_t seq;
    int i = 0;
    
    while (i++ < ba->ba_winsize) {
        /* gaps may exist */
        if (ba->ba_buf[ba->ba_head].m != NULL) {
            wh = mtod(ba->ba_buf[ba->ba_head].m,
                      struct ieee80211_frame *);
            _KASSERT(ieee80211_has_seq(wh));
            seq = letoh16(*(u_int16_t *)wh->i_seq) >>
            IEEE80211_SEQ_SEQ_SHIFT;
            if (!SEQ_LT(seq, max_seq))
                break;
            ieee80211_inputm(ifp, ba->ba_buf[ba->ba_head].m,
                             ni, &ba->ba_buf[ba->ba_head].rxi, ml);
            ba->ba_buf[ba->ba_head].m = NULL;
            ba->ba_gapwait--;
        } else
            ic->ic_stats.is_ht_rx_ba_frame_lost++;
        ba->ba_head = (ba->ba_head + 1) % IEEE80211_BA_MAX_WINSZ;
        /* move window forward */
        ba->ba_winstart = (ba->ba_winstart + 1) & 0xfff;
    }
    ba->ba_winend = (ba->ba_winstart + ba->ba_winsize - 1) & 0xfff;
}

/* Flush a consecutive sequence of frames from the reorder buffer. */
void
ieee80211_input_ba_flush(struct ieee80211com *ic, struct ieee80211_node *ni,
                         struct ieee80211_rx_ba *ba, struct mbuf_list *ml)

{
    struct _ifnet *ifp = &ic->ic_if;
    
    /* Do not re-arm the gap timeout if we made no progress. */
    if (ba->ba_buf[ba->ba_head].m == NULL)
        return;
    
    /* pass reordered MPDUs up to the next MAC process */
    while (ba->ba_buf[ba->ba_head].m != NULL) {
        ieee80211_inputm(ifp, ba->ba_buf[ba->ba_head].m, ni,
                         &ba->ba_buf[ba->ba_head].rxi, ml);
        ba->ba_buf[ba->ba_head].m = NULL;
        ba->ba_gapwait--;
        
        ba->ba_head = (ba->ba_head + 1) % IEEE80211_BA_MAX_WINSZ;
        /* move window forward */
        ba->ba_winstart = (ba->ba_winstart + 1) & 0xfff;
    }
    ba->ba_winend = (ba->ba_winstart + ba->ba_winsize - 1) & 0xfff;
    
    if (timeout_pending(&ba->ba_gap_to))
        timeout_del(&ba->ba_gap_to);
    if (ba->ba_gapwait)
        timeout_add_msec(&ba->ba_gap_to, IEEE80211_BA_GAP_TIMEOUT);
}

/* 
 * Forcibly move the BA window forward to remove a leading gap which has
 * been causing frames to linger in the reordering buffer for too long.
 * A leading gap will occur if a particular A-MPDU subframe never arrives
 * or if a bug in the sender causes sequence numbers to jump forward by > 1.
 */
int
ieee80211_input_ba_gap_skip(struct ieee80211_rx_ba *ba)
{
    int skipped = 0;

    while (skipped < ba->ba_winsize && ba->ba_buf[ba->ba_head].m == NULL) {
        /* move window forward */
        ba->ba_head = (ba->ba_head + 1) % IEEE80211_BA_MAX_WINSZ;
        ba->ba_winstart = (ba->ba_winstart + 1) & 0xfff;
        skipped++;
    }
    if (skipped > 0)
        ba->ba_winend = (ba->ba_winstart + ba->ba_winsize - 1) & 0xfff;

    return skipped;
}

void
ieee80211_input_ba_gap_timeout(void *arg)
{
    struct ieee80211_rx_ba *ba = (struct ieee80211_rx_ba *)arg;
    struct ieee80211_node *ni = ba->ba_ni;
    struct ieee80211com *ic = ni->ni_ic;
    int s, skipped;
    
    ic->ic_stats.is_ht_rx_ba_window_gap_timeout++;
    
    s = splnet();
    
    skipped = ieee80211_input_ba_gap_skip(ba);
    ic->ic_stats.is_ht_rx_ba_frame_lost += skipped;
    if (skipped) {
        struct mbuf_list ml = MBUF_LIST_INITIALIZER();
        ieee80211_input_ba_flush(ic, ni, ba, &ml);
        if_input(&ic->ic_if, &ml);
    }
    
    splx(s);
}


/*
 * Change the value of WinStartB (move window forward) upon reception of a
 * BlockAckReq frame or an ADDBA Request (PBAC).
 */
void
ieee80211_ba_move_window(struct ieee80211com *ic, struct ieee80211_node *ni,
                         u_int8_t tid, u_int16_t ssn, struct mbuf_list *ml)
{
    struct _ifnet *ifp = &ic->ic_if;
    struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid];
    int count;
    
    /* assert(WinStartB <= SSN) */
    
    count = (ssn - ba->ba_winstart) & 0xfff;
    if (count > ba->ba_winsize)    /* no overlap */
        count = ba->ba_winsize;
    while (count-- > 0) {
        /* gaps may exist */
        if (ba->ba_buf[ba->ba_head].m != NULL) {
            ieee80211_inputm(ifp, ba->ba_buf[ba->ba_head].m, ni,
                             &ba->ba_buf[ba->ba_head].rxi, ml);
            ba->ba_buf[ba->ba_head].m = NULL;
            ba->ba_gapwait--;
        } else
            ic->ic_stats.is_ht_rx_ba_frame_lost++;
        ba->ba_head = (ba->ba_head + 1) % IEEE80211_BA_MAX_WINSZ;
    }
    /* move window forward */
    ba->ba_winstart = ssn;
    ba->ba_winend = (ba->ba_winstart + ba->ba_winsize - 1) & 0xfff;
    
    ieee80211_input_ba_flush(ic, ni, ba, ml);
}

void
ieee80211_enqueue_data(struct ieee80211com *ic, mbuf_t m,
                       struct ieee80211_node *ni, int mcast, struct mbuf_list *ml)
{
    struct _ifnet *ifp = &ic->ic_if;
    struct ether_header *eh;
    mbuf_t m1;
    mbuf_t m2;
    
    eh = mtod(m, struct ether_header *);
    
    if ((ic->ic_flags & IEEE80211_F_RSNON) && !ni->ni_port_valid &&
        eh->ether_type != htons(ETHERTYPE_PAE)) {
        DPRINTF(("port not valid: %s\n",
                 ether_sprintf(eh->ether_dhost)));
        ic->ic_stats.is_rx_unauth++;
        mbuf_freem(m);
        return;
    }
    
    /*
     * Perform as a bridge within the AP.  Notice that we do not
     * bridge EAPOL frames as suggested in C.1.1 of IEEE Std 802.1X.
     * And we do not forward unicast frames received on a multicast address.
     */
    m1 = NULL;
#ifndef IEEE80211_STA_ONLY
    if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
        !(ic->ic_userflags & IEEE80211_F_NOBRIDGE) &&
        eh->ether_type != htons(ETHERTYPE_PAE)) {
        struct ieee80211_node *ni1;
        
        if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
            m1 = m_dup_pkt(m, ETHER_ALIGN, MBUF_DONTWAIT);
            if (m1 == NULL) {
                XYLog("%s %d OUTPUT_ERROR\n", __FUNCTION__, __LINE__);
                ifp->netStat->outputErrors++;
            }
            else
                mbuf_setflags(m1, mbuf_flags(m1) | MBUF_MCAST);
        } else if (!mcast) {
            ni1 = ieee80211_find_node(ic, eh->ether_dhost);
            if (ni1 != NULL &&
                ni1->ni_state == IEEE80211_STA_ASSOC) {
                m1 = m;
                m = NULL;
            }
        }
        if (m1 != NULL) {
            if (if_enqueue(ifp, m1)) {
                XYLog("%s %d OUTPUT_ERROR\n", __FUNCTION__, __LINE__);
                ifp->netStat->outputErrors++;
            }
        }
    }
#endif
    if (m != NULL) {
        if ((ic->ic_flags & IEEE80211_F_RSNON) &&
            eh->ether_type == htons(ETHERTYPE_PAE)) {
            ifp->netStat->inputPackets++;
#if NBPFILTER > 0
            /*
             * If we forward frame into transmitter of the AP,
             * we don't need to duplicate for DLT_EN10MB.
             */
            if (ifp->if_bpf && m1 == NULL)
                bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_IN);
#endif
#ifdef USE_APPLE_SUPPLICANT
            ml_enqueue(ml, m);
#else
#ifdef IO80211FAMILY_V2
            if (ieee80211_is_8021x_akm((enum ieee80211_akm)ni->ni_rsnakms)) {
                XYLog("%s Duplicate EAPOL packet to user space\n", __FUNCTION__);
                mbuf_dup(m, MBUF_DONTWAIT, &m2);
                if (m2 != NULL)
                    ifp->iface->inputPacket(m2, mbuf_len(m2));
            }
#endif
            ieee80211_eapol_key_input(ic, m, ni);
#endif
        } else {
            ml_enqueue(ml, m);
        }
    }
}

void
ieee80211_decap(struct ieee80211com *ic, mbuf_t m,
                struct ieee80211_node *ni, int hdrlen, struct mbuf_list *ml)
{
    struct ether_header eh;
    struct ieee80211_frame *wh;
    struct llc *llc;
    int mcast;
    
    if (mbuf_len(m) < hdrlen + LLC_SNAPFRAMELEN &&
        mbuf_pullup(&m, hdrlen + LLC_SNAPFRAMELEN)) {
        ic->ic_stats.is_rx_decap++;
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    mcast = IEEE80211_IS_MULTICAST(wh->i_addr1);
    switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
        case IEEE80211_FC1_DIR_NODS:
            IEEE80211_ADDR_COPY(eh.ether_dhost, wh->i_addr1);
            IEEE80211_ADDR_COPY(eh.ether_shost, wh->i_addr2);
            break;
        case IEEE80211_FC1_DIR_TODS:
            IEEE80211_ADDR_COPY(eh.ether_dhost, wh->i_addr3);
            IEEE80211_ADDR_COPY(eh.ether_shost, wh->i_addr2);
            break;
        case IEEE80211_FC1_DIR_FROMDS:
            IEEE80211_ADDR_COPY(eh.ether_dhost, wh->i_addr1);
            IEEE80211_ADDR_COPY(eh.ether_shost, wh->i_addr3);
            break;
        case IEEE80211_FC1_DIR_DSTODS:
            IEEE80211_ADDR_COPY(eh.ether_dhost, wh->i_addr3);
            IEEE80211_ADDR_COPY(eh.ether_shost,
                                ((struct ieee80211_frame_addr4 *)wh)->i_addr4);
            break;
    }
    llc = (struct llc *)((caddr_t)wh + hdrlen);
    if (llc->llc_dsap == LLC_SNAP_LSAP &&
        llc->llc_ssap == LLC_SNAP_LSAP &&
        llc->llc_control == LLC_UI &&
        llc->llc_snap.org_code[0] == 0 &&
        llc->llc_snap.org_code[1] == 0 &&
        llc->llc_snap.org_code[2] == 0) {
        eh.ether_type = llc->llc_snap.ether_type;
        mbuf_adj(m, hdrlen + LLC_SNAPFRAMELEN - ETHER_HDR_LEN);
    } else {
        eh.ether_type = htons(mbuf_pkthdr_len(m) - hdrlen);
        mbuf_adj(m, hdrlen - ETHER_HDR_LEN);
    }
    memcpy(mtod(m, caddr_t), &eh, ETHER_HDR_LEN);
    if (!ALIGNED_POINTER(mtod(m, caddr_t) + ETHER_HDR_LEN, u_int32_t)) {
        mbuf_t m0 = m;
        m = m_dup_pkt(m0, ETHER_ALIGN, M_NOWAIT);
        mbuf_freem(m0);
        if (m == NULL) {
            ic->ic_stats.is_rx_decap++;
            return;
        }
    }
    ieee80211_enqueue_data(ic, m, ni, mcast, ml);
}

int
ieee80211_amsdu_decap_validate(struct ieee80211com *ic, mbuf_t m,
                               struct ieee80211_node *ni)
{
    struct ether_header *eh = mtod(m, struct ether_header *);
    const uint8_t llc_hdr_mac[ETHER_ADDR_LEN] = {
        /* MAC address matching the 802.2 LLC header. */
        LLC_SNAP_LSAP, LLC_SNAP_LSAP, LLC_UI, 0, 0, 0
    }; 
    
    /*
     * We are sorry, but this particular MAC address cannot be used.
     * This mitigates an attack where a single 802.11 frame is interpreted
     * as an A-MSDU because of a forged AMSDU-present bit in the 802.11
     * QoS frame header: https://papers.mathyvanhoef.com/usenix2021.pdf
     * See Section 7.2, 'Countermeasures for the design flaws'
     */
    if (ETHER_IS_EQ(eh->ether_dhost, llc_hdr_mac))
        return 1;
    
    switch (ic->ic_opmode) {
#ifndef IEEE80211_STA_ONLY
        case IEEE80211_M_HOSTAP:
            /*
             * Subframes must use the source address of the node which
             * transmitted the A-MSDU. Prevents MAC spoofing.
             */
            if (!ETHER_IS_EQ(ni->ni_macaddr, eh->ether_shost))
                return 1;
            break;
#endif
        case IEEE80211_M_STA:
            /* Subframes must be addressed to me. */
            if (!ETHER_IS_EQ(ic->ic_myaddr, eh->ether_dhost))
                return 1;
            break;
        default:
            /* Ignore MONITOR/IBSS modes for now. */
            break;
    }
    
    return 0;
}

/*
 * Decapsulate an Aggregate MSDU (see 7.2.2.2).
 */
void
ieee80211_amsdu_decap(struct ieee80211com *ic, mbuf_t m,
                      struct ieee80211_node *ni, int hdrlen, struct mbuf_list *ml)
{
    mbuf_t n;
    struct ether_header *eh;
    struct llc *llc;
    int len, pad, mcast;
    struct ieee80211_frame *wh;
    struct mbuf_list subframes = MBUF_LIST_INITIALIZER();
    
    wh = mtod(m, struct ieee80211_frame *);
    mcast = IEEE80211_IS_MULTICAST(wh->i_addr1);
    
    /* strip 802.11 header */
    mbuf_adj(m, hdrlen);
    
    while (mbuf_pkthdr_len(m) >= ETHER_HDR_LEN + LLC_SNAPFRAMELEN) {
        /* process an A-MSDU subframe */
        mbuf_pullup(&m, ETHER_HDR_LEN + LLC_SNAPFRAMELEN);
        if (m == NULL)
            break;
        eh = mtod(m, struct ether_header *);
        /* examine 802.3 header */
        len = ntohs(eh->ether_type);
        if (len < LLC_SNAPFRAMELEN) {
            DPRINTF(("A-MSDU subframe too short (%d)\n", len));
            /* stop processing A-MSDU subframes */
            ic->ic_stats.is_rx_decap++;
            ml_purge(&subframes);
            mbuf_freem(m);
            return;
        }
        llc = (struct llc *)&eh[1];
        /* Examine the 802.2 LLC header after the A-MSDU header. */
        if (llc->llc_dsap == LLC_SNAP_LSAP &&
            llc->llc_ssap == LLC_SNAP_LSAP &&
            llc->llc_control == LLC_UI &&
            llc->llc_snap.org_code[0] == 0 &&
            llc->llc_snap.org_code[1] == 0 &&
            llc->llc_snap.org_code[2] == 0) {
            /* convert to Ethernet II header */
            eh->ether_type = llc->llc_snap.ether_type;
            /* strip LLC+SNAP headers */
            memmove((u_int8_t *)eh + LLC_SNAPFRAMELEN, eh,
                    ETHER_HDR_LEN);
            mbuf_adj(m, LLC_SNAPFRAMELEN);
            len -= LLC_SNAPFRAMELEN;
        }
        len += ETHER_HDR_LEN;
        if (len > mbuf_pkthdr_len(m)) {
            /* stop processing A-MSDU subframes */
            DPRINTF(("A-MSDU subframe too long (%d)\n", len));
            ic->ic_stats.is_rx_decap++;
            ml_purge(&subframes);
            mbuf_freem(m);
            return;
        }
        
        /* "detach" our A-MSDU subframe from the others */
        mbuf_split(m, len, MBUF_DONTWAIT, &n);
        if (n == NULL) {
            /* stop processing A-MSDU subframes */
            ic->ic_stats.is_rx_decap++;
            ml_purge(&subframes);
            mbuf_freem(m);
            return;
        }
        
        if (ieee80211_amsdu_decap_validate(ic, m, ni)) {
            /* stop processing A-MSDU subframes */
            ic->ic_stats.is_rx_decap++;
            ml_purge(&subframes);
            mbuf_freem(m);
            return;
        }
        
        ml_enqueue(&subframes, m);
        
        m = n;
        /* remove padding */
        pad = ((len + 3) & ~3) - len;
        mbuf_adj(m, pad);
    }
    
    while ((n = ml_dequeue(&subframes)) != NULL)
        ieee80211_enqueue_data(ic, n, ni, mcast, ml);
    
    mbuf_freem(m);
}

/*
 * Parse an EDCA Parameter Set element (see 7.3.2.27).
 */
int
ieee80211_parse_edca_params_body(struct ieee80211com *ic, const u_int8_t *frm)
{
    u_int updtcount;
    int aci;
    
    /*
     * Check if EDCA parameters have changed XXX if we miss more than
     * 15 consecutive beacons, we might not detect changes to EDCA
     * parameters due to wraparound of the 4-bit Update Count field.
     */
    updtcount = frm[0] & 0xf;
    if (updtcount == ic->ic_edca_updtcount)
        return 0;    /* no changes to EDCA parameters, ignore */
    ic->ic_edca_updtcount = updtcount;
    
    frm += 2;    /* skip QoS Info & Reserved fields */
    
    /* parse AC Parameter Records */
    for (aci = 0; aci < EDCA_NUM_AC; aci++) {
        struct ieee80211_edca_ac_params *ac = &ic->ic_edca_ac[aci];
        
        ac->ac_acm       = (frm[0] >> 4) & 0x1;
        ac->ac_aifsn     = frm[0] & 0xf;
        ac->ac_ecwmin    = frm[1] & 0xf;
        ac->ac_ecwmax    = frm[1] >> 4;
        ac->ac_txoplimit = LE_READ_2(frm + 2);
        frm += 4;
    }
    /* give drivers a chance to update their settings */
    if ((ic->ic_flags & IEEE80211_F_QOS) && ic->ic_updateedca != NULL)
        (*ic->ic_updateedca)(ic);
    
    return 0;
}

int
ieee80211_parse_edca_params(struct ieee80211com *ic, const u_int8_t *frm)
{
    if (frm[1] < 18) {
        ic->ic_stats.is_rx_elem_toosmall++;
        return IEEE80211_REASON_IE_INVALID;
    }
    return ieee80211_parse_edca_params_body(ic, frm + 2);
}

int
ieee80211_parse_wmm_params(struct ieee80211com *ic, const u_int8_t *frm)
{
    if (frm[1] < 24) {
        ic->ic_stats.is_rx_elem_toosmall++;
        return IEEE80211_REASON_IE_INVALID;
    }
    return ieee80211_parse_edca_params_body(ic, frm + 8);
}

enum ieee80211_cipher
ieee80211_parse_rsn_cipher(const u_int8_t selector[4])
{
    if (memcmp(selector, MICROSOFT_OUI, 3) == 0) {    /* WPA */
        switch (selector[3]) {
            case 0:    /* use group data cipher suite */
                return IEEE80211_CIPHER_USEGROUP;
            case 1:    /* WEP-40 */
                return IEEE80211_CIPHER_WEP40;
            case 2:    /* TKIP */
                return IEEE80211_CIPHER_TKIP;
            case 4:    /* CCMP (RSNA default) */
                return IEEE80211_CIPHER_CCMP;
            case 5:    /* WEP-104 */
                return IEEE80211_CIPHER_WEP104;
        }
    } else if (memcmp(selector, IEEE80211_OUI, 3) == 0) {    /* RSN */
        /* see 802.11-2012 Table 8-99 */
        switch (selector[3]) {
            case 0:    /* use group data cipher suite */
                return IEEE80211_CIPHER_USEGROUP;
            case 1:    /* WEP-40 */
                return IEEE80211_CIPHER_WEP40;
            case 2:    /* TKIP */
                return IEEE80211_CIPHER_TKIP;
            case 4:    /* CCMP (RSNA default) */
                return IEEE80211_CIPHER_CCMP;
            case 5:    /* WEP-104 */
                return IEEE80211_CIPHER_WEP104;
            case 6:    /* BIP */
                return IEEE80211_CIPHER_BIP;
        }
    }
    return IEEE80211_CIPHER_NONE;    /* ignore unknown ciphers */
}

enum ieee80211_akm
ieee80211_parse_rsn_akm(const u_int8_t selector[4])
{
    if (memcmp(selector, MICROSOFT_OUI, 3) == 0) {    /* WPA */
        switch (selector[3]) {
            case 1:    /* IEEE 802.1X (RSNA default) */
                return IEEE80211_AKM_8021X;
            case 2:    /* PSK */
                return IEEE80211_AKM_PSK;
        }
    } else if (memcmp(selector, IEEE80211_OUI, 3) == 0) {    /* RSN */
        /* from IEEE Std 802.11i-2004 - Table 20dc */
        switch (selector[3]) {
            case 1:    /* IEEE 802.1X (RSNA default) */
                return IEEE80211_AKM_8021X;
            case 2:    /* PSK */
                return IEEE80211_AKM_PSK;
            case 5:    /* IEEE 802.1X with SHA256 KDF */
                return IEEE80211_AKM_SHA256_8021X;
            case 6:    /* PSK with SHA256 KDF */
                return IEEE80211_AKM_SHA256_PSK;
        }
    }
    return IEEE80211_AKM_NONE;    /* ignore unknown AKMs */
}

/*
 * Parse an RSN element (see 802.11-2012 8.4.2.27)
 */
int
ieee80211_parse_rsn_body(struct ieee80211com *ic, const u_int8_t *frm,
                         u_int len, struct ieee80211_rsnparams *rsn)
{
    const u_int8_t *efrm;
    u_int16_t m, n, s;
    
    efrm = frm + len;
    
    /* check Version field */
    if (LE_READ_2(frm) != 1)
        return IEEE80211_STATUS_RSN_IE_VER_UNSUP;
    frm += 2;
    
    /* all fields after the Version field are optional */
    
    /* if Cipher Suite missing, default to CCMP */
    rsn->rsn_groupcipher = IEEE80211_CIPHER_CCMP;
    rsn->rsn_nciphers = 1;
    rsn->rsn_ciphers = IEEE80211_CIPHER_CCMP;
    /* if Group Management Cipher Suite missing, defaut to BIP */
    rsn->rsn_groupmgmtcipher = IEEE80211_CIPHER_BIP;
    /* if AKM Suite missing, default to 802.1X */
    rsn->rsn_nakms = 1;
    rsn->rsn_akms = IEEE80211_AKM_8021X;
    /* if RSN capabilities missing, default to 0 */
    rsn->rsn_caps = 0;
    rsn->rsn_npmkids = 0;
    
    /* read Group Data Cipher Suite field */
    if (frm + 4 > efrm)
        return 0;
    rsn->rsn_groupcipher = ieee80211_parse_rsn_cipher(frm);
    if (rsn->rsn_groupcipher == IEEE80211_CIPHER_NONE ||
        rsn->rsn_groupcipher == IEEE80211_CIPHER_USEGROUP ||
        rsn->rsn_groupcipher == IEEE80211_CIPHER_BIP)
        return IEEE80211_STATUS_BAD_GROUP_CIPHER;
    frm += 4;
    
    /* read Pairwise Cipher Suite Count field */
    if (frm + 2 > efrm)
        return 0;
    m = rsn->rsn_nciphers = LE_READ_2(frm);
    frm += 2;
    
    /* read Pairwise Cipher Suite List */
    if (frm + m * 4 > efrm)
        return IEEE80211_STATUS_IE_INVALID;
    rsn->rsn_ciphers = IEEE80211_CIPHER_NONE;
    while (m-- > 0) {
        rsn->rsn_ciphers |= ieee80211_parse_rsn_cipher(frm);
        frm += 4;
    }
    if (rsn->rsn_ciphers & IEEE80211_CIPHER_USEGROUP) {
        if (rsn->rsn_ciphers != IEEE80211_CIPHER_USEGROUP)
            return IEEE80211_STATUS_BAD_PAIRWISE_CIPHER;
        if (rsn->rsn_groupcipher == IEEE80211_CIPHER_CCMP)
            return IEEE80211_STATUS_BAD_PAIRWISE_CIPHER;
    }
    
    /* read AKM Suite List Count field */
    if (frm + 2 > efrm)
        return 0;
    n = rsn->rsn_nakms = LE_READ_2(frm);
    frm += 2;
    
    /* read AKM Suite List */
    if (frm + n * 4 > efrm)
        return IEEE80211_STATUS_IE_INVALID;
    rsn->rsn_akms = IEEE80211_AKM_NONE;
    while (n-- > 0) {
        rsn->rsn_akms |= ieee80211_parse_rsn_akm(frm);
        frm += 4;
    }
    
    /* read RSN Capabilities field */
    if (frm + 2 > efrm)
        return 0;
    rsn->rsn_caps = LE_READ_2(frm);
    frm += 2;
    
    /* read PMKID Count field */
    if (frm + 2 > efrm)
        return 0;
    s = rsn->rsn_npmkids = LE_READ_2(frm);
    frm += 2;
    
    /* read PMKID List */
    if (frm + s * IEEE80211_PMKID_LEN > efrm)
        return IEEE80211_STATUS_IE_INVALID;
    if (s != 0) {
        rsn->rsn_pmkids = frm;
        frm += s * IEEE80211_PMKID_LEN;
    }
    
    /* read Group Management Cipher Suite field */
    if (frm + 4 > efrm)
        return 0;
    rsn->rsn_groupmgmtcipher = ieee80211_parse_rsn_cipher(frm);
    if (rsn->rsn_groupmgmtcipher != IEEE80211_CIPHER_BIP)
        return IEEE80211_STATUS_BAD_GROUP_CIPHER;
    
    return IEEE80211_STATUS_SUCCESS;
}

int
ieee80211_parse_rsn(struct ieee80211com *ic, const u_int8_t *frm,
                    struct ieee80211_rsnparams *rsn)
{
    if (frm[1] < 2) {
        ic->ic_stats.is_rx_elem_toosmall++;
        return IEEE80211_STATUS_IE_INVALID;
    }
    return ieee80211_parse_rsn_body(ic, frm + 2, frm[1], rsn);
}

int
ieee80211_parse_wpa(struct ieee80211com *ic, const u_int8_t *frm,
                    struct ieee80211_rsnparams *rsn)
{
    if (frm[1] < 6) {
        ic->ic_stats.is_rx_elem_toosmall++;
        return IEEE80211_STATUS_IE_INVALID;
    }
    return ieee80211_parse_rsn_body(ic, frm + 6, frm[1] - 4, rsn);
}

/*
 * Create (or update) a copy of an information element.
 */
int
ieee80211_save_ie(const u_int8_t *frm, u_int8_t **ie)
{
    int olen = *ie ? 2 + (*ie)[1] : 0;
    int len = 2 + frm[1];
    
    if (*ie == NULL || olen != len) {
        if (*ie != NULL)
            free(*ie);
        *ie = (u_int8_t *)malloc(len, 0, 0);
        if (*ie == NULL)
            return ENOMEM;
    }
    memcpy(*ie, frm, len);
    return 0;
}

/*
 * zxy, save tlv ie for Apple80211
 */
int
ieee80211_save_ie_tlv(const u_int8_t *frm, u_int8_t **ie, uint32_t *accept_len, uint32_t len)
{
    int olen = *accept_len;
    
    if (*ie == NULL || olen != len) {
        if (*ie != NULL && *accept_len > 0)
            free(*ie);
        *ie = (u_int8_t *)malloc(len, 1, 1);
        if (*ie == NULL)
            return ENOMEM;
    }
    *accept_len = len;
    memcpy(*ie, frm, len);
    return 0;
}

/*-
 * Beacon/Probe response frame format:
 * [8]   Timestamp
 * [2]   Beacon interval
 * [2]   Capability
 * [tlv] Service Set Identifier (SSID)
 * [tlv] Supported rates
 * [tlv] DS Parameter Set (802.11g)
 * [tlv] ERP Information (802.11g)
 * [tlv] Extended Supported Rates (802.11g)
 * [tlv] RSN (802.11i)
 * [tlv] EDCA Parameter Set (802.11e)
 * [tlv] QoS Capability (Beacon only, 802.11e)
 * [tlv] HT Capabilities (802.11n)
 * [tlv] HT Operation (802.11n)
 */
void
ieee80211_recv_probe_resp(struct ieee80211com *ic, mbuf_t m,
                          struct ieee80211_node *rni, struct ieee80211_rxinfo *rxi, int isprobe)
{
    struct ieee80211_node *ni = NULL;
    const struct ieee80211_frame *wh;
    const u_int8_t *frm, *efrm;
    const u_int8_t *tstamp, *ssid, *rates, *xrates, *edcaie, *wmmie;
    const u_int8_t *rsnie, *wpaie, *htcaps, *htop;
    const uint8_t *csa;
    const uint8_t *vhtcap;
    const uint8_t *vhtopmode;
    const uint8_t *hecap;
    const uint8_t *heopmode;
    u_int16_t capinfo, bintval;
    u_int8_t chan, bchan, erp, dtim_count, dtim_period;
    int is_new;
    
    /*
     * We process beacon/probe response frames for:
     *    o station mode: to collect state
     *      updates such as 802.11g slot time and for passive
     *      scanning of APs
     *    o adhoc mode: to discover neighbors
     *    o hostap mode: for passive scanning of neighbor APs
     *    o when scanning
     * In other words, in all modes other than monitor (which
     * does not process incoming frames) and adhoc-demo (which
     * does not use management frames at all).
     */
#ifdef DIAGNOSTIC
    if (ic->ic_opmode != IEEE80211_M_STA &&
#ifndef IEEE80211_STA_ONLY
        ic->ic_opmode != IEEE80211_M_IBSS &&
        ic->ic_opmode != IEEE80211_M_HOSTAP &&
#endif
        ic->ic_state != IEEE80211_S_SCAN) {
        panic("%s: impossible operating mode", __func__);
    }
#endif
    /* make sure all mandatory fixed fields are present */
    if (mbuf_len(m) < sizeof(*wh) + 12) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    efrm = mtod(m, u_int8_t *) + mbuf_len(m);
    
    tstamp  = frm; frm += 8;
    bintval = LE_READ_2(frm); frm += 2;
    capinfo = LE_READ_2(frm); frm += 2;
    
    ssid = rates = xrates = edcaie = wmmie = rsnie = wpaie = csa = vhtcap = vhtopmode = hecap = heopmode = NULL;
    htcaps = htop = NULL;
    if (rxi->rxi_chan)
         bchan = rxi->rxi_chan;
     else
         bchan = ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan);
    chan = bchan;
    erp = 0;
    dtim_count = dtim_period = 0;
    while (frm + 2 <= efrm) {
        if (frm + 2 + frm[1] > efrm) {
            ic->ic_stats.is_rx_elem_toosmall++;
            break;
        }
        switch (frm[0]) {
            case IEEE80211_ELEMID_SSID:
                ssid = frm;
                break;
            case IEEE80211_ELEMID_CSA:
                csa = frm;
                break;
            case IEEE80211_ELEMID_RATES:
                rates = frm;
                break;
            case IEEE80211_ELEMID_DSPARMS:
                if (frm[1] < 1) {
                    ic->ic_stats.is_rx_elem_toosmall++;
                    break;
                }
                chan = frm[2];
                break;
            case IEEE80211_ELEMID_XRATES:
                xrates = frm;
                break;
            case IEEE80211_ELEMID_ERP:
                if (frm[1] < 1) {
                    ic->ic_stats.is_rx_elem_toosmall++;
                    break;
                }
                erp = frm[2];
                break;
            case IEEE80211_ELEMID_VHT_CAP:
                vhtcap = frm;
                break;
            case IEEE80211_ELEMID_VHT_OPMODE:
                vhtopmode = frm;
                break;
            case IEEE80211_ELEMID_RSN:
                rsnie = frm;
                break;
            case IEEE80211_ELEMID_EDCAPARMS:
                edcaie = frm;
                break;
            case IEEE80211_ELEMID_HTCAPS:
                htcaps = frm;
                break;
            case IEEE80211_ELEMID_HTOP:
                htop = frm;
                break;
            case IEEE80211_ELEMID_TIM:
                if (frm[1] > 3) {
                    dtim_count = frm[2];
                    dtim_period = frm[3];
                }
                break;
            case IEEE80211_ELEMID_VENDOR:
                if (frm[1] < 4) {
                    ic->ic_stats.is_rx_elem_toosmall++;
                    break;
                }
                if (memcmp(frm + 2, MICROSOFT_OUI, 3) == 0) {
                    if (frm[5] == 1)
                        wpaie = frm;
                    else if (frm[1] >= 5 &&
                             frm[5] == 2 && frm[6] == 1)
                        wmmie = frm;
                }
                break;
            case IEEE80211_ELEMID_EXTENSION:
                switch (frm[2]) {
                    case IEEE80211_ELEMID_EXT_HE_MU_EDCA:
                        break;
                    case IEEE80211_ELEMID_EXT_HE_CAPABILITY:
                        hecap = frm;
                        break;
                    case IEEE80211_ELEMID_EXT_HE_OPERATION:
                        heopmode = frm;
                        break;
                    case IEEE80211_ELEMID_EXT_UORA:
                        break;
                    case IEEE80211_ELEMID_EXT_MAX_CHANNEL_SWITCH_TIME:
                        break;
                    case IEEE80211_ELEMID_EXT_MULTIPLE_BSSID_CONFIGURATION:
                        break;
                    case IEEE80211_ELEMID_EXT_HE_SPR:
                        break;
                    case IEEE80211_ELEMID_EXT_HE_6GHZ_CAPA:
                        break;
                }
                break;
        }
        frm += 2 + frm[1];
    }
    /* supported rates element is mandatory */
    if (rates == NULL || rates[1] > IEEE80211_RATE_MAXSIZE) {
        DPRINTF(("invalid supported rates element\n"));
        return;
    }
    /* SSID element is mandatory */
    if (ssid == NULL || ssid[1] > IEEE80211_NWID_LEN) {
        DPRINTF(("invalid SSID element\n"));
        return;
    }
    if (csa != NULL && csa[1] < 3 * sizeof(uint8_t)) {
        DPRINTF(("csa ie too short, got %d, expected %lu\n", csa[1], 3 * sizeof(uint8_t)));
        csa = NULL;
    }
    if (vhtcap != NULL && vhtcap[1] < sizeof(struct ieee80211_ie_vhtcap) - 2) {
        DPRINTF(("vhtcap ie too short, got %d, expected %lu\n", vhtcap[1], sizeof(struct ieee80211_ie_vhtcap) - 2));
        vhtcap = NULL;
    }
    if (vhtopmode != NULL && vhtopmode[1] < sizeof(struct ieee80211_ie_vht_operation) - 2) {
        DPRINTF(("vhtopmode ie too short, got %d, expected %lu\n", vhtopmode[1], sizeof(struct ieee80211_ie_vht_operation) - 2));
        vhtopmode = NULL;
    }
    if (
#if IEEE80211_CHAN_MAX < 255
        chan > IEEE80211_CHAN_MAX ||
#endif
        (isclr(ic->ic_chan_active, chan) &&
         ((ic->ic_caps & IEEE80211_C_SCANALL) == 0 ||
          (ic->ic_flags & IEEE80211_F_BGSCAN) == 0))) {
        DPRINTF(("ignore %s with invalid channel %u\n",
                 isprobe ? "probe response" : "beacon", chan));
        ic->ic_stats.is_rx_badchan++;
        return;
    }
    if ((rxi->rxi_chan != 0 && chan != rxi->rxi_chan) ||
        ((ic->ic_state != IEEE80211_S_SCAN ||
         !(ic->ic_caps & IEEE80211_C_SCANALL)) &&
        chan != bchan)) {
        /*
         * Frame was received on a channel different from the
         * one indicated in the DS params element id;
         * silently discard it.
         *
         * NB: this can happen due to signal leakage.
         */
        DPRINTF(("ignore %s on channel %u marked for channel %u\n",
                 isprobe ? "probe response" : "beacon", bchan, chan));
        ic->ic_stats.is_rx_chanmismatch++;
        return;
    }
    
#ifdef IEEE80211_DEBUG
    if (ieee80211_debug > 1 &&
        (ni == NULL || ic->ic_state == IEEE80211_S_SCAN ||
         (ic->ic_flags & IEEE80211_F_BGSCAN))) {
        XYLog("%s: %s%s on chan %u (bss chan %u) ",
              __func__, (ni == NULL ? "new " : ""),
              isprobe ? "probe response" : "beacon",
              chan, bchan);
        ieee80211_print_essid(ssid + 2, ssid[1]);
        XYLog(" from %s\n", ether_sprintf((u_int8_t *)wh->i_addr2));
        XYLog("%s: caps 0x%x bintval %u erp 0x%x\n",
              __func__, capinfo, bintval, erp);
    }
#endif
    
    if ((ni = ieee80211_find_node(ic, wh->i_addr2)) == NULL) {
        ni = ieee80211_alloc_node(ic, wh->i_addr2);
        if (ni == NULL)
            return;
        is_new = 1;
    } else
        is_new = 0;
    
    ni->ni_chan = &ic->ic_channels[chan];
    
    if (htcaps)
        ieee80211_setup_htcaps(ni, htcaps + 2, htcaps[1]);
    if (htop && !ieee80211_setup_htop(ni, htop + 2, htop[1], 1))
        htop = NULL; /* invalid HTOP */
    
    if (vhtcap != NULL && vhtopmode != NULL) {
        ieee80211_setup_vhtcaps(ic, ni, vhtcap);
        ieee80211_setup_vhtopmode(ni, vhtopmode);
    }
    if (hecap != NULL && heopmode != NULL) {
        ieee80211_setup_hecaps(ni, hecap + 3, hecap[1] - 1);
        ieee80211_setup_heop(ni, heopmode + 3, heopmode[1] - 1);
    }
    
    ni->ni_dtimcount = dtim_count;
    ni->ni_dtimperiod = dtim_period;
#ifdef AIRPORT
    ni->ni_age_ts = airport_up_time();
#endif
    
    /*
     * When operating in station mode, check for state updates
     * while we're associated.
     */
    if (ic->ic_opmode == IEEE80211_M_STA &&
        ic->ic_state == IEEE80211_S_RUN &&
        ni->ni_state == IEEE80211_STA_BSS) {
        int updateprot = 0;
        /*
         * Check if protection mode has changed since last beacon.
         */
        if (ni->ni_erp != erp) {
            DPRINTF(("[%s] erp change: was 0x%x, now 0x%x\n",
                     ether_sprintf((u_int8_t *)wh->i_addr2),
                     ni->ni_erp, erp));
            if ((ic->ic_curmode == IEEE80211_MODE_11G ||
                 (ic->ic_curmode == IEEE80211_MODE_11N &&
                  IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))) &&
                (erp & IEEE80211_ERP_USE_PROTECTION))
                ic->ic_flags |= IEEE80211_F_USEPROT;
            else
                ic->ic_flags &= ~IEEE80211_F_USEPROT;
            ic->ic_bss->ni_erp = erp;
            updateprot = 1;
        }
        if (htop && (ic->ic_bss->ni_flags & IEEE80211_NODE_HT)) {
            enum ieee80211_htprot htprot_last, htprot;
            htprot_last =
            (enum ieee80211_htprot)((ic->ic_bss->ni_htop1 & IEEE80211_HTOP1_PROT_MASK)
                                    >> IEEE80211_HTOP1_PROT_SHIFT);
            htprot = (enum ieee80211_htprot)((ni->ni_htop1 & IEEE80211_HTOP1_PROT_MASK) >>
                                             IEEE80211_HTOP1_PROT_SHIFT);
            if (htprot_last != htprot) {
                DPRINTF(("[%s] htprot change: was %d, now %d\n",
                         ether_sprintf((u_int8_t *)wh->i_addr2),
                         htprot_last, htprot));
                ic->ic_stats.is_ht_prot_change++;
                ic->ic_bss->ni_htop1 = ni->ni_htop1;
                updateprot = 1;
            }
        }
        if (updateprot && ic->ic_updateprot != NULL)
            ic->ic_updateprot(ic);

        /*
         * Check if 40MHz channel mode has changed since last beacon.
         */
        if (htop && !(ic->ic_bss->ni_flags & IEEE80211_NODE_VHT) &&
            !(ic->ic_bss->ni_flags & IEEE80211_NODE_HE) &&
            (ic->ic_bss->ni_flags & IEEE80211_NODE_HT) &&
            (ic->ic_htcaps & IEEE80211_HTCAP_CBW20_40)) {
            uint8_t chw_last, chw, sco_last, sco;
            chw_last = (ic->ic_bss->ni_htop0 & IEEE80211_HTOP0_CHW);
            chw = (ni->ni_htop0 & IEEE80211_HTOP0_CHW);
            sco_last =
            ((ic->ic_bss->ni_htop0 & IEEE80211_HTOP0_SCO_MASK)
             >> IEEE80211_HTOP0_SCO_SHIFT);
            sco = ((ni->ni_htop0 & IEEE80211_HTOP0_SCO_MASK) >>
                   IEEE80211_HTOP0_SCO_SHIFT);
            ic->ic_bss->ni_htop0 = ni->ni_htop0;
            if (chw_last != chw || sco_last != sco) {
                XYLog("[%s] channel mode change: was %d, now %d, sco was: %d, now: %d\n",
                      ether_sprintf((u_int8_t *)wh->i_addr2),
                      chw_last, chw, sco_last, sco);
                if (ic->ic_update_chw != NULL)
                    ic->ic_update_chw(ic);
            }
        } else if (htop)
            ic->ic_bss->ni_htop0 = ni->ni_htop0;
        
        /*
         * Check if AP short slot time setting has changed
         * since last beacon and give the driver a chance to
         * update the hardware.
         */
        if ((ni->ni_capinfo ^ capinfo) &
            IEEE80211_CAPINFO_SHORT_SLOTTIME) {
            ieee80211_set_shortslottime(ic,
                                        ic->ic_curmode == IEEE80211_MODE_11A ||
                                        (capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME));
        }
        
        if (!ic->ic_bss->ni_dtimperiod) {
            ic->ic_bss->ni_dtimcount = ni->ni_dtimcount;
            ic->ic_bss->ni_dtimperiod = ni->ni_dtimperiod ?: 1;
            
            if (ic->ic_updatedtim != NULL)
                ic->ic_updatedtim(ic);
        }
        
        /*
         * Reset management timer. If it is non-zero in RUN state, the
         * driver sent a probe request after a missed beacon event.
         * This probe response indicates the AP is still serving us
         * so don't allow ieee80211_watchdog() to move us into SCAN.
         */
        if ((ic->ic_flags & IEEE80211_F_BGSCAN) == 0)
            ic->ic_mgt_timer = 0;
    }
    /*
     * We do not try to update EDCA parameters if QoS was not negotiated
     * with the AP at association time.
     */
    if (ni->ni_flags & IEEE80211_NODE_QOS) {
        /* always prefer EDCA IE over Wi-Fi Alliance WMM IE */
        if ((edcaie != NULL &&
             ieee80211_parse_edca_params(ic, edcaie) == 0) ||
            (wmmie != NULL &&
             ieee80211_parse_wmm_params(ic, wmmie) == 0))
            ni->ni_flags |= IEEE80211_NODE_QOS;
        else
            ni->ni_flags &= ~IEEE80211_NODE_QOS;
    }
    
    if (ic->ic_state == IEEE80211_S_SCAN ||
        (ic->ic_flags & IEEE80211_F_BGSCAN)) {
        struct ieee80211_rsnparams rsn, wpa;
        
        uint32_t tlv_len = (mtod(m, u_int8_t *) + mbuf_len(m)) - (u_int8_t *)&wh[1] + 1 - 8 - 2 - 2;
        ieee80211_save_ie_tlv(((u_int8_t *)&wh[1]) + 8 + 2 + 2, &ni->ni_rsnie_tlv, &ni->ni_rsnie_tlv_len, tlv_len);
        ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
        ni->ni_supported_rsnprotos = IEEE80211_PROTO_NONE;
        ni->ni_rsnakms = 0;
        ni->ni_supported_rsnakms = 0;
        ni->ni_rsnciphers = 0;
        ni->ni_rsngroupcipher = (enum ieee80211_cipher)0;
        ni->ni_rsngroupmgmtcipher = (enum ieee80211_cipher)0;
        ni->ni_rsncaps = 0;
        
        if (rsnie != NULL &&
            ieee80211_parse_rsn(ic, rsnie, &rsn) == 0) {
            ni->ni_supported_rsnprotos |= IEEE80211_PROTO_RSN;
            ni->ni_supported_rsnakms |= rsn.rsn_akms;
        }
        if (wpaie != NULL &&
            ieee80211_parse_wpa(ic, wpaie, &wpa) == 0) {
            ni->ni_supported_rsnprotos |= IEEE80211_PROTO_WPA;
            ni->ni_supported_rsnakms |= wpa.rsn_akms;
        }
        
        /*
         * If the AP advertises both WPA and RSN IEs (WPA1+WPA2),
         * we only use the highest protocol version we support.
         */
        if (rsnie != NULL &&
            (ni->ni_supported_rsnprotos & IEEE80211_PROTO_RSN) &&
            (ic->ic_caps & IEEE80211_C_RSN)) {
            if (ieee80211_save_ie(rsnie, &ni->ni_rsnie) == 0
#ifndef IEEE80211_STA_ONLY
                && ic->ic_opmode != IEEE80211_M_HOSTAP
#endif
                ) {
                ni->ni_rsnprotos = IEEE80211_PROTO_RSN;
                ni->ni_rsnakms = rsn.rsn_akms;
                ni->ni_rsnciphers = rsn.rsn_ciphers;
                ni->ni_rsngroupcipher = rsn.rsn_groupcipher;
                ni->ni_rsngroupmgmtcipher =
                rsn.rsn_groupmgmtcipher;
                ni->ni_rsncaps = rsn.rsn_caps;
            }
        } else if (wpaie != NULL &&
                   (ni->ni_supported_rsnprotos & IEEE80211_PROTO_WPA) &&
                   (ic->ic_caps & IEEE80211_C_RSN)) {
            if (ieee80211_save_ie(wpaie, &ni->ni_rsnie) == 0
#ifndef IEEE80211_STA_ONLY
                && ic->ic_opmode != IEEE80211_M_HOSTAP
#endif
                ) {
                ni->ni_rsnprotos = IEEE80211_PROTO_WPA;
                ni->ni_rsnakms = wpa.rsn_akms;
                ni->ni_rsnciphers = wpa.rsn_ciphers;
                ni->ni_rsngroupcipher = wpa.rsn_groupcipher;
                ni->ni_rsngroupmgmtcipher =
                wpa.rsn_groupmgmtcipher;
                ni->ni_rsncaps = wpa.rsn_caps;
            }
        }
    }
    
    /*
     * Set our SSID if we do not know it yet.
     * If we are doing a directed scan for an AP with a hidden SSID
     * we must collect the SSID from a probe response to override
     * a non-zero-length SSID filled with zeroes that we may have
     * received earlier in a beacon.
     */
    if (ssid[1] != 0 && ni->ni_essid[0] == '\0') {
        ni->ni_esslen = ssid[1];
        memset(ni->ni_essid, 0, sizeof(ni->ni_essid));
        /* we know that ssid[1] <= IEEE80211_NWID_LEN */
        memcpy(ni->ni_essid, &ssid[2], ssid[1]);
    }
    IEEE80211_ADDR_COPY(ni->ni_bssid, wh->i_addr3);
    if (ic->ic_state == IEEE80211_S_SCAN &&
        IEEE80211_IS_CHAN_5GHZ(ni->ni_chan)) {
        /*
         * During a scan on 5Ghz, prefer RSSI measured for probe
         * response frames. i.e. don't allow beacons to lower the
         * measured RSSI. Some 5GHz APs send beacons with much
         * less Tx power than they use for probe responses.
         */
        if (isprobe || ni->ni_rssi == 0)
            ni->ni_rssi = rxi->rxi_rssi;
        else if (ni->ni_rssi < rxi->rxi_rssi)
            ni->ni_rssi = rxi->rxi_rssi;
    } else
        ni->ni_rssi = rxi->rxi_rssi;
    ni->ni_rstamp = rxi->rxi_tstamp;
    memcpy(ni->ni_tstamp, tstamp, sizeof(ni->ni_tstamp));
    ni->ni_intval = bintval;
    ni->ni_capinfo = capinfo;
    ni->ni_erp = erp;
    /* NB: must be after ni_chan is setup */
    ieee80211_setup_rates(ic, ni, rates, xrates, IEEE80211_F_DOSORT);
#ifndef IEEE80211_STA_ONLY
    if (ic->ic_opmode == IEEE80211_M_IBSS && is_new && isprobe) {
        /*
         * Fake an association so the driver can setup it's
         * private state.  The rate set has been setup above;
         * there is no handshake as in ap/station operation.
         */
        if (ic->ic_newassoc)
            (*ic->ic_newassoc)(ic, ni, 1);
    }
#endif
}

#ifndef IEEE80211_STA_ONLY
/*-
 * Probe request frame format:
 * [tlv] SSID
 * [tlv] Supported rates
 * [tlv] Extended Supported Rates (802.11g)
 * [tlv] HT Capabilities (802.11n)
 */
void
ieee80211_recv_probe_req(struct ieee80211com *ic, mbuf_t m,
                         struct ieee80211_node *ni, struct ieee80211_rxinfo *rxi)
{
    const struct ieee80211_frame *wh;
    const u_int8_t *frm, *efrm;
    const u_int8_t *ssid, *rates, *xrates, *htcaps;
    u_int8_t rate;
    
    if (ic->ic_opmode == IEEE80211_M_STA ||
        ic->ic_state != IEEE80211_S_RUN)
        return;
    
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    efrm = mtod(m, u_int8_t *) + mbuf_len(m);
    
    ssid = rates = xrates = htcaps = NULL;
    while (frm + 2 <= efrm) {
        if (frm + 2 + frm[1] > efrm) {
            ic->ic_stats.is_rx_elem_toosmall++;
            break;
        }
        switch (frm[0]) {
            case IEEE80211_ELEMID_SSID:
                ssid = frm;
                break;
            case IEEE80211_ELEMID_RATES:
                rates = frm;
                break;
            case IEEE80211_ELEMID_XRATES:
                xrates = frm;
                break;
            case IEEE80211_ELEMID_HTCAPS:
                htcaps = frm;
                break;
        }
        frm += 2 + frm[1];
    }
    /* supported rates element is mandatory */
    if (rates == NULL || rates[1] > IEEE80211_RATE_MAXSIZE) {
        DPRINTF(("invalid supported rates element\n"));
        return;
    }
    /* SSID element is mandatory */
    if (ssid == NULL || ssid[1] > IEEE80211_NWID_LEN) {
        DPRINTF(("invalid SSID element\n"));
        return;
    }
    /* check that the specified SSID (if not wildcard) matches ours */
    if (ssid[1] != 0 && (ssid[1] != ic->ic_bss->ni_esslen ||
                         memcmp(&ssid[2], ic->ic_bss->ni_essid, ic->ic_bss->ni_esslen))) {
        DPRINTF(("SSID mismatch\n"));
        ic->ic_stats.is_rx_ssidmismatch++;
        return;
    }
    /* refuse wildcard SSID if we're hiding our SSID in beacons */
    if (ssid[1] == 0 && (ic->ic_userflags & IEEE80211_F_HIDENWID)) {
        DPRINTF(("wildcard SSID rejected"));
        ic->ic_stats.is_rx_ssidmismatch++;
        return;
    }
    
    if (ni == ic->ic_bss) {
        ni = ieee80211_find_node(ic, wh->i_addr2);
        if (ni == NULL)
            ni = ieee80211_dup_bss(ic, wh->i_addr2);
        if (ni == NULL)
            return;
        DPRINTF(("new probe req from %s\n",
                 ether_sprintf((u_int8_t *)wh->i_addr2)));
    }
    ni->ni_rssi = rxi->rxi_rssi;
    ni->ni_rstamp = rxi->rxi_tstamp;
    rate = ieee80211_setup_rates(ic, ni, rates, xrates,
                                 IEEE80211_F_DOSORT | IEEE80211_F_DOFRATE | IEEE80211_F_DONEGO |
                                 IEEE80211_F_DODEL);
    if (rate & IEEE80211_RATE_BASIC) {
        DPRINTF(("rate mismatch for %s\n",
                 ether_sprintf((u_int8_t *)wh->i_addr2)));
        return;
    }
    if (htcaps)
        ieee80211_setup_htcaps(ni, htcaps + 2, htcaps[1]);
    else
        ieee80211_clear_htcaps(ni);
    IEEE80211_SEND_MGMT(ic, ni, IEEE80211_FC0_SUBTYPE_PROBE_RESP, 0);
}
#endif	/* IEEE80211_STA_ONLY */

/*-
 * Authentication frame format:
 * [2] Authentication algorithm number
 * [2] Authentication transaction sequence number
 * [2] Status code
 */
void
ieee80211_recv_auth(struct ieee80211com *ic, mbuf_t m,
                    struct ieee80211_node *ni, struct ieee80211_rxinfo *rxi)
{
    const struct ieee80211_frame *wh;
    const u_int8_t *frm;
    u_int16_t algo, seq, status;
    
    /* make sure all mandatory fixed fields are present */
    if (mbuf_len(m) < sizeof(*wh) + 6) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    
    algo   = LE_READ_2(frm); frm += 2;
    seq    = LE_READ_2(frm); frm += 2;
    status = LE_READ_2(frm); frm += 2;
    DPRINTF(("auth %d seq %d from %s\n", algo, seq,
             ether_sprintf((u_int8_t *)wh->i_addr2)));
    
    /* only "open" auth mode is supported */
    if (algo != IEEE80211_AUTH_ALG_OPEN) {
        DPRINTF(("unsupported auth algorithm %d from %s\n",
                 algo, ether_sprintf((u_int8_t *)wh->i_addr2)));
        ic->ic_stats.is_rx_auth_unsupported++;
#ifndef IEEE80211_STA_ONLY
        if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
            /* XXX hack to workaround calling convention */
            IEEE80211_SEND_MGMT(ic, ni,
                                IEEE80211_FC0_SUBTYPE_AUTH,
                                IEEE80211_STATUS_ALG << 16 | ((seq + 1) & 0xfff));
        }
#endif
        return;
    }
    ic->ic_deauth_reason = IEEE80211_REASON_UNSPECIFIED;
    ic->ic_assoc_status = 0xffff;
    ieee80211_auth_open(ic, wh, ni, rxi, seq, status);
}

#ifndef IEEE80211_STA_ONLY
/*-
 * (Re)Association request frame format:
 * [2]   Capability information
 * [2]   Listen interval
 * [6*]  Current AP address (Reassociation only)
 * [tlv] SSID
 * [tlv] Supported rates
 * [tlv] Extended Supported Rates (802.11g)
 * [tlv] RSN (802.11i)
 * [tlv] QoS Capability (802.11e)
 * [tlv] HT Capabilities (802.11n)
 */
void
ieee80211_recv_assoc_req(struct ieee80211com *ic, mbuf_t m,
                         struct ieee80211_node *ni, struct ieee80211_rxinfo *rxi, int reassoc)
{
    const struct ieee80211_frame *wh;
    const u_int8_t *frm, *efrm;
    const u_int8_t *ssid, *rates, *xrates, *rsnie, *wpaie, *wmeie, *htcaps;
    u_int16_t capinfo, bintval;
    int resp, status = 0;
    struct ieee80211_rsnparams rsn;
    u_int8_t rate;
    const u_int8_t *saveie = NULL;
    
    if (ic->ic_opmode != IEEE80211_M_HOSTAP ||
        ic->ic_state != IEEE80211_S_RUN)
        return;
    
    /* make sure all mandatory fixed fields are present */
    if (mbuf_len(m) < sizeof(*wh) + (reassoc ? 10 : 4)) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    efrm = mtod(m, u_int8_t *) + mbuf_len(m);
    
    if (!IEEE80211_ADDR_EQ(wh->i_addr3, ic->ic_bss->ni_bssid)) {
        DPRINTF(("ignore other bss from %s\n",
                 ether_sprintf((u_int8_t *)wh->i_addr2)));
        ic->ic_stats.is_rx_assoc_bss++;
        return;
    }
    capinfo = LE_READ_2(frm); frm += 2;
    bintval = LE_READ_2(frm); frm += 2;
//    uint32_t tlv_len = (mtod(m, u_int8_t *) + mbuf_len(m)) - (u_int8_t *)&wh[1] + 1 - 2 - 2;
//    ieee80211_save_ie_tlv(frm, &ni->ni_rsnie_tlv, &ni->ni_rsnie_tlv_len, tlv_len);
    if (reassoc) {
        frm += IEEE80211_ADDR_LEN;    /* skip current AP address */
        resp = IEEE80211_FC0_SUBTYPE_REASSOC_RESP;
    } else
        resp = IEEE80211_FC0_SUBTYPE_ASSOC_RESP;
    
    ssid = rates = xrates = rsnie = wpaie = wmeie = htcaps = NULL;
    while (frm + 2 <= efrm) {
        if (frm + 2 + frm[1] > efrm) {
            ic->ic_stats.is_rx_elem_toosmall++;
            break;
        }
        switch (frm[0]) {
            case IEEE80211_ELEMID_SSID:
                ssid = frm;
                break;
            case IEEE80211_ELEMID_RATES:
                rates = frm;
                break;
            case IEEE80211_ELEMID_XRATES:
                xrates = frm;
                break;
            case IEEE80211_ELEMID_RSN:
                rsnie = frm;
                break;
            case IEEE80211_ELEMID_QOS_CAP:
                break;
            case IEEE80211_ELEMID_HTCAPS:
                htcaps = frm;
                break;
            case IEEE80211_ELEMID_VENDOR:
                if (frm[1] < 4) {
                    ic->ic_stats.is_rx_elem_toosmall++;
                    break;
                }
                if (memcmp(frm + 2, MICROSOFT_OUI, 3) == 0) {
                    if (frm[5] == 1)
                        wpaie = frm;
                    /* WME info IE: len=7 type=2 subtype=0 */
                    if (frm[1] == 7 && frm[5] == 2 && frm[6] == 0)
                        wmeie = frm;
                }
                break;
        }
        frm += 2 + frm[1];
    }
    /* supported rates element is mandatory */
    if (rates == NULL || rates[1] > IEEE80211_RATE_MAXSIZE) {
        DPRINTF(("invalid supported rates element\n"));
        return;
    }
    /* SSID element is mandatory */
    if (ssid == NULL || ssid[1] > IEEE80211_NWID_LEN) {
        DPRINTF(("invalid SSID element\n"));
        return;
    }
    /* check that the specified SSID matches ours */
    if (ssid[1] != ic->ic_bss->ni_esslen ||
        memcmp(&ssid[2], ic->ic_bss->ni_essid, ic->ic_bss->ni_esslen)) {
        DPRINTF(("SSID mismatch\n"));
        ic->ic_stats.is_rx_ssidmismatch++;
        return;
    }
    
    if (ni->ni_state != IEEE80211_STA_AUTH &&
        ni->ni_state != IEEE80211_STA_ASSOC) {
        DPRINTF(("deny %sassoc from %s, not authenticated\n",
                 reassoc ? "re" : "",
                 ether_sprintf((u_int8_t *)wh->i_addr2)));
        ni = ieee80211_find_node(ic, wh->i_addr2);
        if (ni == NULL)
            ni = ieee80211_dup_bss(ic, wh->i_addr2);
        if (ni != NULL) {
            IEEE80211_SEND_MGMT(ic, ni,
                                IEEE80211_FC0_SUBTYPE_DEAUTH,
                                IEEE80211_REASON_ASSOC_NOT_AUTHED);
        }
        ic->ic_stats.is_rx_assoc_notauth++;
        return;
    }
    
    if (ni->ni_state == IEEE80211_STA_ASSOC &&
        (ni->ni_flags & IEEE80211_NODE_MFP)) {
        if (ni->ni_flags & IEEE80211_NODE_SA_QUERY_FAILED) {
            /* send a protected Disassociate frame */
            IEEE80211_SEND_MGMT(ic, ni,
                                IEEE80211_FC0_SUBTYPE_DISASSOC,
                                IEEE80211_REASON_AUTH_EXPIRE);
            /* terminate the old SA */
            ieee80211_node_leave(ic, ni);
        } else {
            /* reject the (Re)Association Request temporarily */
            IEEE80211_SEND_MGMT(ic, ni, resp,
                                IEEE80211_STATUS_TRY_AGAIN_LATER);
            /* start SA Query procedure if not already engaged */
            if (!(ni->ni_flags & IEEE80211_NODE_SA_QUERY))
                ieee80211_sa_query_request(ic, ni);
            /* do not modify association state */
        }
        return;
    }
    
    if (!(capinfo & IEEE80211_CAPINFO_ESS)) {
        ic->ic_stats.is_rx_assoc_capmismatch++;
        status = IEEE80211_STATUS_CAPINFO;
        goto end;
    }
    rate = ieee80211_setup_rates(ic, ni, rates, xrates,
                                 IEEE80211_F_DOSORT | IEEE80211_F_DOFRATE | IEEE80211_F_DONEGO |
                                 IEEE80211_F_DODEL);
    if (rate & IEEE80211_RATE_BASIC) {
        ic->ic_stats.is_rx_assoc_norate++;
        status = IEEE80211_STATUS_BASIC_RATE;
        goto end;
    }
    
    ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
    ni->ni_supported_rsnprotos = IEEE80211_PROTO_NONE;
    ni->ni_rsnakms = 0;
    ni->ni_supported_rsnakms = 0;
    ni->ni_rsnciphers = 0;
    ni->ni_rsngroupcipher = (enum ieee80211_cipher)0;
    ni->ni_rsngroupmgmtcipher = (enum ieee80211_cipher)0;
    ni->ni_rsncaps = 0;
    
    /*
     * A station should never include both a WPA and an RSN IE
     * in its (Re)Association Requests, but if it does, we only
     * consider the IE of the highest version of the protocol
     * that is allowed (ie RSN over WPA).
     */
    if (rsnie != NULL) {
        status = ieee80211_parse_rsn(ic, rsnie, &rsn);
        if (status != 0)
            goto end;
        ni->ni_supported_rsnprotos = IEEE80211_PROTO_RSN;
        ni->ni_supported_rsnakms = rsn.rsn_akms;
        if ((ic->ic_flags & IEEE80211_F_RSNON) &&
            (ic->ic_rsnprotos & IEEE80211_PROTO_RSN)) {
            ni->ni_rsnprotos = IEEE80211_PROTO_RSN;
            saveie = rsnie;
        }
    } else if (wpaie != NULL) {
        status = ieee80211_parse_wpa(ic, wpaie, &rsn);
        if (status != 0)
            goto end;
        ni->ni_supported_rsnprotos = IEEE80211_PROTO_WPA;
        ni->ni_supported_rsnakms = rsn.rsn_akms;
        if ((ic->ic_flags & IEEE80211_F_RSNON) &&
            (ic->ic_rsnprotos & IEEE80211_PROTO_WPA)) {
            ni->ni_rsnprotos = IEEE80211_PROTO_WPA;
            saveie = wpaie;
        }
    }
    
    if (ic->ic_flags & IEEE80211_F_QOS) {
        if (wmeie != NULL)
            ni->ni_flags |= IEEE80211_NODE_QOS;
        else    /* for Reassociation */
            ni->ni_flags &= ~IEEE80211_NODE_QOS;
    }
    
    if (ic->ic_flags & IEEE80211_F_RSNON) {
        if (ni->ni_rsnprotos == IEEE80211_PROTO_NONE) {
            /*
             * In an RSN, an AP shall not associate with STAs
             * that fail to include the RSN IE in the
             * (Re)Association Request.
             */
            status = IEEE80211_STATUS_IE_INVALID;
            goto end;
        }
        /*
         * The initiating STA's RSN IE shall include one authentication
         * and pairwise cipher suite among those advertised by the
         * targeted AP.  It shall also specify the group cipher suite
         * specified by the targeted AP.
         */
        if (rsn.rsn_nakms != 1 ||
            !(rsn.rsn_akms & ic->ic_bss->ni_rsnakms)) {
            status = IEEE80211_STATUS_BAD_AKMP;
            ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
            goto end;
        }
        if (rsn.rsn_nciphers != 1 ||
            !(rsn.rsn_ciphers & ic->ic_bss->ni_rsnciphers)) {
            status = IEEE80211_STATUS_BAD_PAIRWISE_CIPHER;
            ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
            goto end;
        }
        if (rsn.rsn_groupcipher != ic->ic_bss->ni_rsngroupcipher) {
            status = IEEE80211_STATUS_BAD_GROUP_CIPHER;
            ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
            goto end;
        }
        
        if ((ic->ic_bss->ni_rsncaps & IEEE80211_RSNCAP_MFPR) &&
            !(rsn.rsn_caps & IEEE80211_RSNCAP_MFPC)) {
            status = IEEE80211_STATUS_MFP_POLICY;
            ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
            goto end;
        }
        if ((ic->ic_bss->ni_rsncaps & IEEE80211_RSNCAP_MFPC) &&
            (rsn.rsn_caps & (IEEE80211_RSNCAP_MFPC |
                             IEEE80211_RSNCAP_MFPR)) == IEEE80211_RSNCAP_MFPR) {
            /* STA advertises an invalid setting */
            status = IEEE80211_STATUS_MFP_POLICY;
            ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
            goto end;
        }
        /*
         * A STA that has associated with Management Frame Protection
         * enabled shall not use cipher suite pairwise selector WEP40,
         * WEP104, TKIP, or "Use Group cipher suite".
         */
        if ((rsn.rsn_caps & IEEE80211_RSNCAP_MFPC) &&
            (rsn.rsn_ciphers != IEEE80211_CIPHER_CCMP ||
             rsn.rsn_groupmgmtcipher !=
             ic->ic_bss->ni_rsngroupmgmtcipher)) {
            status = IEEE80211_STATUS_MFP_POLICY;
            ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
            goto end;
        }
        
        /*
         * Disallow new associations using TKIP if countermeasures
         * are active.
         */
        if ((ic->ic_flags & IEEE80211_F_COUNTERM) &&
            (rsn.rsn_ciphers == IEEE80211_CIPHER_TKIP ||
             rsn.rsn_groupcipher == IEEE80211_CIPHER_TKIP)) {
            status = IEEE80211_STATUS_CIPHER_REJ_POLICY;
            ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
            goto end;
        }
        
        /* everything looks fine, save IE and parameters */
        if (saveie == NULL ||
            ieee80211_save_ie(saveie, &ni->ni_rsnie) != 0) {
            status = IEEE80211_STATUS_TOOMANY;
            ni->ni_rsnprotos = IEEE80211_PROTO_NONE;
            goto end;
        }
        ni->ni_rsnakms = rsn.rsn_akms;
        ni->ni_rsnciphers = rsn.rsn_ciphers;
        ni->ni_rsngroupcipher = ic->ic_bss->ni_rsngroupcipher;
        ni->ni_rsngroupmgmtcipher = ic->ic_bss->ni_rsngroupmgmtcipher;
        ni->ni_rsncaps = rsn.rsn_caps;
        
        if (ieee80211_is_8021x_akm((enum ieee80211_akm)ni->ni_rsnakms)) {
            struct ieee80211_pmk *pmk = NULL;
            const u_int8_t *pmkid = rsn.rsn_pmkids;
            /*
             * Check if we have a cached PMK entry matching one
             * of the PMKIDs specified in the RSN IE.
             */
            while (rsn.rsn_npmkids-- > 0) {
                pmk = ieee80211_pmksa_find(ic, ni, pmkid);
                if (pmk != NULL)
                    break;
                pmkid += IEEE80211_PMKID_LEN;
            }
            if (pmk != NULL) {
                memcpy(ni->ni_pmk, pmk->pmk_key,
                       IEEE80211_PMK_LEN);
                memcpy(ni->ni_pmkid, pmk->pmk_pmkid,
                       IEEE80211_PMKID_LEN);
                ni->ni_flags |= IEEE80211_NODE_PMK;
            }
        }
    }
    
    ni->ni_rssi = rxi->rxi_rssi;
    ni->ni_rstamp = rxi->rxi_tstamp;
    ni->ni_intval = bintval;
    ni->ni_capinfo = capinfo;
    ni->ni_chan = ic->ic_bss->ni_chan;
    if (htcaps)
        ieee80211_setup_htcaps(ni, htcaps + 2, htcaps[1]);
    else
        ieee80211_clear_htcaps(ni);
end:
    if (status != 0) {
        IEEE80211_SEND_MGMT(ic, ni, resp, status);
        ieee80211_node_leave(ic, ni);
    } else
        ieee80211_node_join(ic, ni, resp);
}
#endif	/* IEEE80211_STA_ONLY */

/*-
 * (Re)Association response frame format:
 * [2]   Capability information
 * [2]   Status code
 * [2]   Association ID (AID)
 * [tlv] Supported rates
 * [tlv] Extended Supported Rates (802.11g)
 * [tlv] EDCA Parameter Set (802.11e)
 * [tlv] HT Capabilities (802.11n)
 * [tlv] HT Operation (802.11n)
 */
void
ieee80211_recv_assoc_resp(struct ieee80211com *ic, mbuf_t m,
                          struct ieee80211_node *ni, int reassoc)
{
    XYLog("%s reassoc=%d\n", __FUNCTION__, reassoc);
    struct _ifnet *ifp = &ic->ic_if;
    const struct ieee80211_frame *wh;
    const u_int8_t *frm, *efrm;
    const u_int8_t *rates, *xrates, *edcaie, *wmmie, *htcaps, *htop;
    const uint8_t *vhtcap;
    const uint8_t *vhtopmode;
    const uint8_t *hecap;
    const uint8_t *heopmode;
    u_int16_t capinfo, status, associd;
    u_int8_t rate;
    
    if (ic->ic_opmode != IEEE80211_M_STA ||
        ic->ic_state != IEEE80211_S_ASSOC) {
        ic->ic_stats.is_rx_mgtdiscard++;
        return;
    }
    
    /* make sure all mandatory fixed fields are present */
    if (mbuf_len(m) < sizeof(*wh) + 6) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    efrm = mtod(m, u_int8_t *) + mbuf_len(m);
    
    capinfo = LE_READ_2(frm); frm += 2;
    status =  LE_READ_2(frm); frm += 2;

    ic->ic_assoc_status = status;
    if (status == IEEE80211_STATUS_SUCCESS) {
        if (ic->ic_event_handler) {
            (*ic->ic_event_handler)(ic, IEEE80211_EVT_STA_ASSOC_DONE, NULL);
        }
    }
    
    if (status != IEEE80211_STATUS_SUCCESS) {
        if (ifp->if_flags & IFF_DEBUG)
            XYLog("%s: %sassociation failed (status %d)"
                  " for %s\n", ifp->if_xname,
                  reassoc ?  "re" : "",
                  status, ether_sprintf((u_int8_t *)wh->i_addr3));
        if (ni != ic->ic_bss)
            ni->ni_fails++;
        ic->ic_stats.is_rx_auth_fail++;
        return;
    }
    associd = LE_READ_2(frm); frm += 2;
    
    rates = xrates = edcaie = wmmie = htcaps = htop = vhtcap = vhtopmode = hecap = heopmode = NULL;
    while (frm + 2 <= efrm) {
        if (frm + 2 + frm[1] > efrm) {
            ic->ic_stats.is_rx_elem_toosmall++;
            break;
        }
        switch (frm[0]) {
            case IEEE80211_ELEMID_RATES:
                rates = frm;
                break;
            case IEEE80211_ELEMID_XRATES:
                xrates = frm;
                break;
            case IEEE80211_ELEMID_EDCAPARMS:
                edcaie = frm;
                break;
            case IEEE80211_ELEMID_HTCAPS:
                htcaps = frm;
                break;
            case IEEE80211_ELEMID_HTOP:
                htop = frm;
                break;
            case IEEE80211_ELEMID_VHT_CAP:
                vhtcap = frm;
                break;
            case IEEE80211_ELEMID_VHT_OPMODE:
                vhtopmode = frm;
                break;
            case IEEE80211_ELEMID_VENDOR:
                if (frm[1] < 4) {
                    ic->ic_stats.is_rx_elem_toosmall++;
                    break;
                }
                if (memcmp(frm + 2, MICROSOFT_OUI, 3) == 0) {
                    if (frm[1] >= 5 && frm[5] == 2 && frm[6] == 1)
                        wmmie = frm;
                }
                break;
            case IEEE80211_ELEMID_EXTENSION:
                switch (frm[2]) {
                    case IEEE80211_ELEMID_EXT_HE_MU_EDCA:
                        break;
                    case IEEE80211_ELEMID_EXT_HE_CAPABILITY:
                        hecap = frm;
                        break;
                    case IEEE80211_ELEMID_EXT_HE_OPERATION:
                        heopmode = frm;
                        break;
                    case IEEE80211_ELEMID_EXT_UORA:
                        break;
                    case IEEE80211_ELEMID_EXT_MAX_CHANNEL_SWITCH_TIME:
                        break;
                    case IEEE80211_ELEMID_EXT_MULTIPLE_BSSID_CONFIGURATION:
                        break;
                    case IEEE80211_ELEMID_EXT_HE_SPR:
                        break;
                    case IEEE80211_ELEMID_EXT_HE_6GHZ_CAPA:
                        break;
                }
                break;
        }
        frm += 2 + frm[1];
    }
    /* supported rates element is mandatory */
    if (rates == NULL || rates[1] > IEEE80211_RATE_MAXSIZE) {
        DPRINTF(("invalid supported rates element\n"));
        return;
    }
    rate = ieee80211_setup_rates(ic, ni, rates, xrates,
                                 IEEE80211_F_DOSORT | IEEE80211_F_DOFRATE | IEEE80211_F_DONEGO |
                                 IEEE80211_F_DODEL);
    if (rate & IEEE80211_RATE_BASIC) {
        DPRINTF(("rate mismatch for %s\n",
                 ether_sprintf((u_int8_t *)wh->i_addr2)));
        ic->ic_stats.is_rx_assoc_norate++;
        return;
    }
    ni->ni_capinfo = capinfo;
    ni->ni_associd = associd;
    if (edcaie != NULL || wmmie != NULL) {
        /* force update of EDCA parameters */
        ic->ic_edca_updtcount = -1;
        
        if ((edcaie != NULL &&
             ieee80211_parse_edca_params(ic, edcaie) == 0) ||
            (wmmie != NULL &&
             ieee80211_parse_wmm_params(ic, wmmie) == 0))
            ni->ni_flags |= IEEE80211_NODE_QOS;
        else    /* for Reassociation */
            ni->ni_flags &= ~IEEE80211_NODE_QOS;
    }
    if (htcaps)
        ieee80211_setup_htcaps(ni, htcaps + 2, htcaps[1]);
    if (htop)
        ieee80211_setup_htop(ni, htop + 2, htop[1], 0);
    if (vhtcap != NULL && vhtopmode != NULL) {
        ieee80211_setup_vhtcaps(ic, ni, vhtcap);
        ieee80211_setup_vhtopmode(ni, vhtopmode);
    }
    if (hecap != NULL && heopmode != NULL) {
        ieee80211_setup_hecaps(ni, hecap + 3, hecap[1] - 1);
        ieee80211_setup_heop(ni, heopmode + 3, heopmode[1] - 1);
    }

    ieee80211_ht_negotiate(ic, ni);
    ieee80211_vht_negotiate(ic, ni);
    if (hecap != NULL && heopmode != NULL) {
        ieee80211_he_negotiate(ic, ni);
    }
    
    /* Hop into 11n/11ac/11ax mode after associating to an HT AP in a legacy mode. */
    if (ni->ni_flags & IEEE80211_NODE_HE)
        ieee80211_setmode(ic, IEEE80211_MODE_11AX);
    else if (ni->ni_flags & IEEE80211_NODE_VHT)
        ieee80211_setmode(ic, IEEE80211_MODE_11AC);
    else if (ni->ni_flags & IEEE80211_NODE_HT)
        ieee80211_setmode(ic, IEEE80211_MODE_11N);
    else
        ieee80211_setmode(ic, ieee80211_chan2mode(ic, ni->ni_chan));
    
    ieee80211_sta_set_rx_nss(ic, ni);
    /*
     * Reset the erp state (mostly the slot time) now that
     * our operating mode has been nailed down.
     */
    ieee80211_reset_erp(ic);
    
    /*
     * Configure state now that we are associated.
     */
    if (ic->ic_curmode == IEEE80211_MODE_11A ||
        (ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE))
        ic->ic_flags |= IEEE80211_F_SHPREAMBLE;
    else
        ic->ic_flags &= ~IEEE80211_F_SHPREAMBLE;
    
    ieee80211_set_shortslottime(ic,
                                ic->ic_curmode == IEEE80211_MODE_11A ||
                                (ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME));
    /*
     * Honor ERP protection.
     */
    if ((ic->ic_curmode == IEEE80211_MODE_11G ||
         (ic->ic_curmode == IEEE80211_MODE_11N &&
          IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))) &&
        (ni->ni_erp & IEEE80211_ERP_USE_PROTECTION))
        ic->ic_flags |= IEEE80211_F_USEPROT;
    else
        ic->ic_flags &= ~IEEE80211_F_USEPROT;
    /*
     * If not an RSNA, mark the port as valid, otherwise wait for
     * 802.1X authentication and 4-way handshake to complete..
     */
    if (ic->ic_flags & IEEE80211_F_RSNON) {
        /* XXX ic->ic_mgt_timer = 5; */
        ni->ni_rsn_supp_state = RSNA_SUPP_PTKSTART;
    } else if (ic->ic_flags & IEEE80211_F_WEPON)
        ni->ni_flags |= IEEE80211_NODE_TXRXPROT;
    
    ieee80211_new_state(ic, IEEE80211_S_RUN,
                        IEEE80211_FC0_SUBTYPE_ASSOC_RESP);
}

/*-
 * Deauthentication frame format:
 * [2] Reason code
 */
void
ieee80211_recv_deauth(struct ieee80211com *ic, mbuf_t m,
                      struct ieee80211_node *ni)
{
    XYLog("%s\n", __FUNCTION__);
    const struct ieee80211_frame *wh;
    const u_int8_t *frm;
    u_int16_t reason;
    
    /* make sure all mandatory fixed fields are present */
    if (mbuf_len(m) < sizeof(*wh) + 2) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    
    reason = LE_READ_2(frm);

    XYLog("Deauth received, reason %d\n", reason);
    ic->ic_deauth_reason = reason;
    if (ic->ic_event_handler) {
        (*ic->ic_event_handler)(ic, IEEE80211_EVT_STA_DEAUTH, NULL);
    }
    
    ic->ic_stats.is_rx_deauth++;
    switch (ic->ic_opmode) {
        case IEEE80211_M_STA: {
            int bgscan = ((ic->ic_flags & IEEE80211_F_BGSCAN) &&
                          ic->ic_state == IEEE80211_S_RUN);
            int roamscan = bgscan &&
                        (ic->ic_flags & IEEE80211_F_DISABLE_BG_AUTO_CONNECT) == 0;
            int stay_auth = ((ic->ic_userflags & IEEE80211_F_STAYAUTH) &&
                             ic->ic_state >= IEEE80211_S_AUTH);
            if (!(roamscan || stay_auth))
                ieee80211_new_state(ic, IEEE80211_S_AUTH,
                                    IEEE80211_FC0_SUBTYPE_DEAUTH);
        }
            break;
#ifndef IEEE80211_STA_ONLY
        case IEEE80211_M_HOSTAP:
            if (ni != ic->ic_bss) {
                int stay_auth =
                ((ic->ic_userflags & IEEE80211_F_STAYAUTH) &&
                 (ni->ni_state == IEEE80211_STA_AUTH ||
                  ni->ni_state == IEEE80211_STA_ASSOC));
                if (ic->ic_if.if_flags & IFF_DEBUG)
                    XYLog("%s: station %s deauthenticated "
                          "by peer (reason %d)\n",
                          ic->ic_if.if_xname,
                          ether_sprintf(ni->ni_macaddr),
                          reason);
                if (!stay_auth)
                    ieee80211_node_leave(ic, ni);
            }
            break;
#endif
        default:
            break;
    }
}

/*-
 * Disassociation frame format:
 * [2] Reason code
 */
void
ieee80211_recv_disassoc(struct ieee80211com *ic, mbuf_t m,
                        struct ieee80211_node *ni)
{
    XYLog("%s\n", __FUNCTION__);
    const struct ieee80211_frame *wh;
    const u_int8_t *frm;
    u_int16_t reason;
    
    /* make sure all mandatory fixed fields are present */
    if (mbuf_len(m) < sizeof(*wh) + 2) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    
    reason = LE_READ_2(frm);
    
    XYLog("Disassoc received, reason %d\n", reason);
    
    ic->ic_stats.is_rx_disassoc++;
    switch (ic->ic_opmode) {
        case IEEE80211_M_STA: {
            int bgscan = ((ic->ic_flags & IEEE80211_F_BGSCAN) &&
                          ic->ic_state == IEEE80211_S_RUN);
            int roamscan = bgscan &&
                        (ic->ic_flags & IEEE80211_F_DISABLE_BG_AUTO_CONNECT) == 0;
            if (!roamscan) /* ignore disassoc during bgscan */
                ieee80211_new_state(ic, IEEE80211_S_ASSOC,
                                    IEEE80211_FC0_SUBTYPE_DISASSOC);
        }
            break;
#ifndef IEEE80211_STA_ONLY
        case IEEE80211_M_HOSTAP:
            if (ni != ic->ic_bss) {
                if (ic->ic_if.if_flags & IFF_DEBUG)
                    XYLog("%s: station %s disassociated "
                          "by peer (reason %d)\n",
                          ic->ic_if.if_xname,
                          ether_sprintf(ni->ni_macaddr),
                          reason);
                ieee80211_node_leave(ic, ni);
            }
            break;
#endif
        default:
            break;
    }
}

/*-
 * ADDBA Request frame format:
 * [1] Category
 * [1] Action
 * [1] Dialog Token
 * [2] Block Ack Parameter Set
 * [2] Block Ack Timeout Value
 * [2] Block Ack Starting Sequence Control
 */
void
ieee80211_recv_addba_req(struct ieee80211com *ic, mbuf_t m,
                         struct ieee80211_node *ni)
{
    const struct ieee80211_frame *wh;
    const u_int8_t *frm;
    struct ieee80211_rx_ba *ba;
    u_int16_t params, ssn, bufsz, timeout;
    u_int8_t token, tid;
    int err = 0;
    
    /* Ignore if we are not ready to receive data frames. */
    if (ic->ic_state != IEEE80211_S_RUN ||
        ((ic->ic_flags & IEEE80211_F_RSNON) && !ni->ni_port_valid))
        return;
    
    if (!(ni->ni_flags & IEEE80211_NODE_HT)) {
        DPRINTF(("received ADDBA req from non-HT STA %s\n",
                 ether_sprintf(ni->ni_macaddr)));
        return;
    }
    if (mbuf_len(m) < sizeof(*wh) + 9) {
        DPRINTF(("frame too short\n"));
        return;
    }
    
    /* MLME-ADDBA.indication */
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    
    token = frm[2];
    params = LE_READ_2(&frm[3]);
    tid = ((params & IEEE80211_ADDBA_TID_MASK) >>
           IEEE80211_ADDBA_TID_SHIFT);
    bufsz = (params & IEEE80211_ADDBA_BUFSZ_MASK) >>
    IEEE80211_ADDBA_BUFSZ_SHIFT;
    timeout = LE_READ_2(&frm[5]);
    ssn = LE_READ_2(&frm[7]) >> 4;
    
    ba = &ni->ni_rx_ba[tid];
    /* The driver is still processing an ADDBA request for this tid. */
    if (ba->ba_state == IEEE80211_BA_REQUESTED)
        return;
    /* If we are in the process of roaming between APs, ignore. */
    if ((ic->ic_flags & IEEE80211_F_BGSCAN) &&
        ((ic->ic_flags & IEEE80211_F_DISABLE_BG_AUTO_CONNECT) == 0) &&
        (ic->ic_xflags & IEEE80211_F_TX_MGMT_ONLY))
        return;
    /* check if we already have a Block Ack agreement for this RA/TID */
    if (ba->ba_state == IEEE80211_BA_AGREED) {
        /* XXX should we update the timeout value? */
        /* reset Block Ack inactivity timer */
        if (ba->ba_timeout_val != 0)
            timeout_add_usec(&ba->ba_to, ba->ba_timeout_val);
        
        /* check if it's a Protected Block Ack agreement */
        if (!(ni->ni_flags & IEEE80211_NODE_MFP) ||
            !(ni->ni_rsncaps & IEEE80211_RSNCAP_PBAC))
            return;    /* not a PBAC, ignore */
        
        /* PBAC: treat the ADDBA Request like a BlockAckReq */
        if (SEQ_LT(ba->ba_winstart, ssn)) {
            struct mbuf_list ml = MBUF_LIST_INITIALIZER();
            ieee80211_ba_move_window(ic, ni, tid, ssn, &ml);
            if_input(&ic->ic_if, &ml);
        }
        return;
    }
    
    /* if PBAC required but RA does not support it, refuse request */
    if ((ic->ic_flags & IEEE80211_F_PBAR) &&
        (!(ni->ni_flags & IEEE80211_NODE_MFP) ||
         !(ni->ni_rsncaps & IEEE80211_RSNCAP_PBAC)))
        goto refuse;
    /*
     * If the TID for which the Block Ack agreement is requested is
     * configured with a no-ACK policy, refuse the agreement.
     */
    if (ic->ic_tid_noack & (1 << tid))
        goto refuse;
    
    /* check that we support the requested Block Ack Policy */
    if (!(ic->ic_htcaps & IEEE80211_HTCAP_DELAYEDBA) &&
        !(params & IEEE80211_ADDBA_BA_POLICY))
        goto refuse;
    
    /* setup Block Ack agreement */
    ba->ba_state = IEEE80211_BA_REQUESTED;
    ba->ba_timeout_val = timeout * IEEE80211_DUR_TU;
    ba->ba_ni = ni;
    ba->ba_token = token;
    timeout_set(&ba->ba_to, ieee80211_rx_ba_timeout, ba);
    timeout_set(&ba->ba_gap_to, ieee80211_input_ba_gap_timeout, ba);
    ba->ba_gapwait = 0;
    ba->ba_winsize = bufsz;
    if (ba->ba_winsize == 0 || ba->ba_winsize > IEEE80211_BA_MAX_WINSZ)
        ba->ba_winsize = IEEE80211_BA_MAX_WINSZ;
    ba->ba_params = (params & IEEE80211_ADDBA_BA_POLICY);
    ba->ba_params |= ((ba->ba_winsize << IEEE80211_ADDBA_BUFSZ_SHIFT) |
                      (tid << IEEE80211_ADDBA_TID_SHIFT));
    if (ic->ic_caps & IEEE80211_C_AMSDU_IN_AMPDU) {
        ba->ba_params |= IEEE80211_ADDBA_AMSDU;
    }
    ba->ba_winstart = ssn;
    ba->ba_winend = (ba->ba_winstart + ba->ba_winsize - 1) & 0xfff;
    /* allocate and setup our reordering buffer */
    ba->ba_buf = (struct ieee80211_ba_buf*)malloc(IEEE80211_BA_MAX_WINSZ * sizeof(struct ieee80211_ba_buf), 0, 0);
    if (ba->ba_buf == NULL)
        goto refuse;
    
    ba->ba_head = 0;
    
    /* notify drivers of this new Block Ack agreement */
    if (ic->ic_ampdu_rx_start != NULL)
        err = ic->ic_ampdu_rx_start(ic, ni, tid);
    if (err == EBUSY) {
        /* driver will accept or refuse agreement when done */
        return;
    } else if (err) {
        /* driver failed to setup, rollback */
        ieee80211_addba_req_refuse(ic, ni, tid);
    } else
        ieee80211_addba_req_accept(ic, ni, tid);
    return;
    
refuse:
    /* MLME-ADDBA.response */
    IEEE80211_SEND_ACTION(ic, ni, IEEE80211_CATEG_BA,
                          IEEE80211_ACTION_ADDBA_RESP,
                          IEEE80211_STATUS_REFUSED << 16 | token << 8 | tid);
}

void
ieee80211_addba_req_accept(struct ieee80211com *ic, struct ieee80211_node *ni,
                           uint8_t tid)
{
    struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid];
    
    ba->ba_state = IEEE80211_BA_AGREED;
    ic->ic_stats.is_ht_rx_ba_agreements++;
    /* start Block Ack inactivity timer */
    if (ba->ba_timeout_val != 0)
        timeout_add_usec(&ba->ba_to, ba->ba_timeout_val);
    
    /* MLME-ADDBA.response */
    IEEE80211_SEND_ACTION(ic, ni, IEEE80211_CATEG_BA,
                          IEEE80211_ACTION_ADDBA_RESP,
                          IEEE80211_STATUS_SUCCESS << 16 | ba->ba_token << 8 | tid);
}

void
ieee80211_addba_req_refuse(struct ieee80211com *ic, struct ieee80211_node *ni,
                           uint8_t tid)
{
    struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid];
    
    free(ba->ba_buf);
    ba->ba_buf = NULL;
    ba->ba_state = IEEE80211_BA_INIT;
    
    /* MLME-ADDBA.response */
    IEEE80211_SEND_ACTION(ic, ni, IEEE80211_CATEG_BA,
                          IEEE80211_ACTION_ADDBA_RESP,
                          IEEE80211_STATUS_REFUSED << 16 | ba->ba_token << 8 | tid);
}

/*-
 * ADDBA Response frame format:
 * [1] Category
 * [1] Action
 * [1] Dialog Token
 * [2] Status Code
 * [2] Block Ack Parameter Set
 * [2] Block Ack Timeout Value
 */
void
ieee80211_recv_addba_resp(struct ieee80211com *ic, mbuf_t m,
                          struct ieee80211_node *ni)
{
    const struct ieee80211_frame *wh;
    const u_int8_t *frm;
    struct ieee80211_tx_ba *ba;
    u_int16_t status, params, bufsz, timeout;
    u_int8_t token, tid;
    int err = 0;
    
    if (mbuf_len(m) < sizeof(*wh) + 9) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    
    token = frm[2];
    status = LE_READ_2(&frm[3]);
    params = LE_READ_2(&frm[5]);
    tid = (params >> 2) & 0xf;
    bufsz = (params >> 6) & 0x3ff;
    timeout = LE_READ_2(&frm[7]);
    
    DPRINTF(("received ADDBA resp from %s, TID %d, status %d\n",
             ether_sprintf(ni->ni_macaddr), tid, status));
    
    /*
     * Ignore if no ADDBA request has been sent for this RA/TID or
     * if we already have a Block Ack agreement.
     */
    ba = &ni->ni_tx_ba[tid];
    if (ba->ba_state != IEEE80211_BA_REQUESTED) {
        DPRINTF(("no matching ADDBA req found\n"));
        return;
    }
    if (token != ba->ba_token) {
        DPRINTF(("ignoring ADDBA resp from %s: token %x!=%x\n",
                 ether_sprintf(ni->ni_macaddr), token, ba->ba_token));
        return;
    }
    /* we got an ADDBA Response matching our request, stop timeout */
    timeout_del(&ba->ba_to);
    
    if (status != IEEE80211_STATUS_SUCCESS) {
        if (ni->ni_addba_req_intval[tid] <
            IEEE80211_ADDBA_REQ_INTVAL_MAX)
            ni->ni_addba_req_intval[tid]++;
        
        ieee80211_addba_resp_refuse(ic, ni, tid, status);
        
        /*
         * In case the peer believes there is an existing
         * block ack agreement with us, try to delete it.
         */
        IEEE80211_SEND_ACTION(ic, ni, IEEE80211_CATEG_BA,
                              IEEE80211_ACTION_DELBA,
                              IEEE80211_REASON_SETUP_REQUIRED << 16 | 1 << 8 | tid);
        return;
    }
    
    /* notify drivers of this new Block Ack agreement */
    if (ic->ic_ampdu_tx_start != NULL)
        err = ic->ic_ampdu_tx_start(ic, ni, tid);
    
    if (err == EBUSY) {
        /* driver will accept or refuse agreement when done */
        return;
    } else if (err) {
        /* driver failed to setup, rollback */
        ieee80211_addba_resp_refuse(ic, ni, tid,
                                    IEEE80211_STATUS_UNSPECIFIED);
    } else
        ieee80211_addba_resp_accept(ic, ni, tid);
}

void
ieee80211_addba_resp_accept(struct ieee80211com *ic,
                            struct ieee80211_node *ni, uint8_t tid)
{
    struct ieee80211_tx_ba *ba = &ni->ni_tx_ba[tid];
    
    /* MLME-ADDBA.confirm(Success) */
    ba->ba_state = IEEE80211_BA_AGREED;
    ic->ic_stats.is_ht_tx_ba_agreements++;
    
    ni->ni_qos_txseqs[tid] = ba->ba_winstart;
    
    /* Reset ADDBA request interval. */
    ni->ni_addba_req_intval[tid] = 1;
    
    /* start Block Ack inactivity timeout */
    if (ba->ba_timeout_val != 0)
        timeout_add_usec(&ba->ba_to, ba->ba_timeout_val);
}

void
ieee80211_addba_resp_refuse(struct ieee80211com *ic,
                            struct ieee80211_node *ni, uint8_t tid, uint16_t status)
{
    struct ieee80211_tx_ba *ba = &ni->ni_tx_ba[tid];
    
    /* MLME-ADDBA.confirm(Failure) */
    ba->ba_state = IEEE80211_BA_INIT;
}

/*-
 * DELBA frame format:
 * [1] Category
 * [1] Action
 * [2] DELBA Parameter Set
 * [2] Reason Code
 */
void
ieee80211_recv_delba(struct ieee80211com *ic, mbuf_t m,
                     struct ieee80211_node *ni)
{
    const struct ieee80211_frame *wh;
    const u_int8_t *frm;
    u_int16_t params, reason;
    u_int8_t tid;
    int i;
    
    if (mbuf_len(m) < sizeof(*wh) + 6) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    
    params = LE_READ_2(&frm[2]);
    reason = LE_READ_2(&frm[4]);
    tid = params >> 12;
    
    XYLog("received DELBA from %s, TID %d, reason %d\n",
             ether_sprintf(ni->ni_macaddr), tid, reason);
    
    if (params & IEEE80211_DELBA_INITIATOR) {
        /* MLME-DELBA.indication(Originator) */
        struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid];
        
        if (ba->ba_state != IEEE80211_BA_AGREED) {
            DPRINTF(("no matching Block Ack agreement\n"));
            return;
        }
        /* notify drivers of the end of the Block Ack agreement */
        if (ic->ic_ampdu_rx_stop != NULL)
            ic->ic_ampdu_rx_stop(ic, ni, tid);
        
        ba->ba_state = IEEE80211_BA_INIT;
        /* stop Block Ack inactivity timer */
        timeout_del(&ba->ba_to);
        timeout_del(&ba->ba_gap_to);
        ba->ba_gapwait = 0;
        
        if (ba->ba_buf != NULL) {
            /* free all MSDUs stored in reordering buffer */
            for (i = 0; i < IEEE80211_BA_MAX_WINSZ; i++)
                mbuf_freem(ba->ba_buf[i].m);
            /* free reordering buffer */
            free(ba->ba_buf);
            ba->ba_buf = NULL;
        }
    } else {
        /* MLME-DELBA.indication(Recipient) */
        struct ieee80211_tx_ba *ba = &ni->ni_tx_ba[tid];
        
        if (ba->ba_state != IEEE80211_BA_AGREED) {
            DPRINTF(("no matching Block Ack agreement\n"));
            return;
        }
        /* notify drivers of the end of the Block Ack agreement */
        if (ic->ic_ampdu_tx_stop != NULL)
            ic->ic_ampdu_tx_stop(ic, ni, tid);
        
        ba->ba_state = IEEE80211_BA_INIT;
        /* stop Block Ack inactivity timer */
        timeout_del(&ba->ba_to);
    }
}

/*-
 * SA Query Request frame format:
 * [1] Category
 * [1] Action
 * [2] Transaction Identifier
 */
void
ieee80211_recv_sa_query_req(struct ieee80211com *ic, mbuf_t m,
                            struct ieee80211_node *ni)
{
    const struct ieee80211_frame *wh;
    const u_int8_t *frm;
    
    if (ic->ic_opmode != IEEE80211_M_STA ||
        !(ni->ni_flags & IEEE80211_NODE_MFP)) {
        DPRINTF(("unexpected SA Query req from %s\n",
                 ether_sprintf(ni->ni_macaddr)));
        return;
    }
    if (mbuf_len(m) < sizeof(*wh) + 4) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    
    /* MLME-SAQuery.indication */
    
    /* save Transaction Identifier for SA Query Response */
    ni->ni_sa_query_trid = LE_READ_2(&frm[2]);
    
    /* MLME-SAQuery.response */
    IEEE80211_SEND_ACTION(ic, ni, IEEE80211_CATEG_SA_QUERY,
                          IEEE80211_ACTION_SA_QUERY_RESP, 0);
}

#ifndef IEEE80211_STA_ONLY
/*-
 * SA Query Response frame format:
 * [1] Category
 * [1] Action
 * [2] Transaction Identifier
 */
void
ieee80211_recv_sa_query_resp(struct ieee80211com *ic, mbuf_t m,
                             struct ieee80211_node *ni)
{
    const struct ieee80211_frame *wh;
    const u_int8_t *frm;
    
    /* ignore if we're not engaged in an SA Query with that STA */
    if (!(ni->ni_flags & IEEE80211_NODE_SA_QUERY)) {
        DPRINTF(("unexpected SA Query resp from %s\n",
                 ether_sprintf(ni->ni_macaddr)));
        return;
    }
    if (mbuf_len(m) < sizeof(*wh) + 4) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    
    /* check that Transaction Identifier matches */
    if (ni->ni_sa_query_trid != LE_READ_2(&frm[2])) {
        DPRINTF(("transaction identifier does not match\n"));
        return;
    }
    /* MLME-SAQuery.confirm */
    timeout_del(&ni->ni_sa_query_to);
    ni->ni_flags &= ~IEEE80211_NODE_SA_QUERY;
}
#endif

/*-
 * Action frame format:
 * [1] Category
 * [1] Action
 */
void
ieee80211_recv_action(struct ieee80211com *ic, mbuf_t m,
                      struct ieee80211_node *ni)
{
    const struct ieee80211_frame *wh;
    const u_int8_t *frm;
    
    if (mbuf_len(m) < sizeof(*wh) + 2) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame *);
    frm = (const u_int8_t *)&wh[1];
    
    switch (frm[0]) {
        case IEEE80211_CATEG_BA:
            switch (frm[1]) {
                case IEEE80211_ACTION_ADDBA_REQ:
                    ieee80211_recv_addba_req(ic, m, ni);
                    break;
                case IEEE80211_ACTION_ADDBA_RESP:
                    ieee80211_recv_addba_resp(ic, m, ni);
                    break;
                case IEEE80211_ACTION_DELBA:
                    ieee80211_recv_delba(ic, m, ni);
                    break;
            }
            break;
        case IEEE80211_CATEG_SA_QUERY:
            switch (frm[1]) {
                case IEEE80211_ACTION_SA_QUERY_REQ:
                    ieee80211_recv_sa_query_req(ic, m, ni);
                    break;
#ifndef IEEE80211_STA_ONLY
                case IEEE80211_ACTION_SA_QUERY_RESP:
                    ieee80211_recv_sa_query_resp(ic, m, ni);
                    break;
#endif
            }
            break;
        default:
            DPRINTF(("action frame category %d not handled\n", frm[0]));
            break;
    }
}

void
ieee80211_recv_mgmt(struct ieee80211com *ic, mbuf_t m,
                    struct ieee80211_node *ni, struct ieee80211_rxinfo *rxi, int subtype)
{
    switch (subtype) {
        case IEEE80211_FC0_SUBTYPE_BEACON:
            ieee80211_recv_probe_resp(ic, m, ni, rxi, 0);
            break;
        case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
            ieee80211_recv_probe_resp(ic, m, ni, rxi, 1);
            break;
#ifndef IEEE80211_STA_ONLY
        case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
            ieee80211_recv_probe_req(ic, m, ni, rxi);
            break;
#endif
        case IEEE80211_FC0_SUBTYPE_AUTH:
            ieee80211_recv_auth(ic, m, ni, rxi);
            break;
#ifndef IEEE80211_STA_ONLY
        case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
            ieee80211_recv_assoc_req(ic, m, ni, rxi, 0);
            break;
        case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
            ieee80211_recv_assoc_req(ic, m, ni, rxi, 1);
            break;
#endif
        case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
            ieee80211_recv_assoc_resp(ic, m, ni, 0);
            break;
        case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
            ieee80211_recv_assoc_resp(ic, m, ni, 1);
            break;
        case IEEE80211_FC0_SUBTYPE_DEAUTH:
            ieee80211_recv_deauth(ic, m, ni);
            break;
        case IEEE80211_FC0_SUBTYPE_DISASSOC:
            ieee80211_recv_disassoc(ic, m, ni);
            break;
        case IEEE80211_FC0_SUBTYPE_ACTION:
            ieee80211_recv_action(ic, m, ni);
            break;
        default:
            DPRINTF(("mgmt frame with subtype 0x%x not handled\n",
                     subtype));
            ic->ic_stats.is_rx_badsubtype++;
            break;
    }
}

#ifndef IEEE80211_STA_ONLY
/*
 * Process an incoming PS-Poll control frame (see 11.2).
 */
void
ieee80211_recv_pspoll(struct ieee80211com *ic, mbuf_t m,
                      struct ieee80211_node *ni)
{
    struct _ifnet *ifp = &ic->ic_if;
    struct ieee80211_frame_pspoll *psp;
    struct ieee80211_frame *wh;
    u_int16_t aid;
    
    if (ic->ic_opmode != IEEE80211_M_HOSTAP ||
        !(ic->ic_caps & IEEE80211_C_APPMGT) ||
        ni->ni_state != IEEE80211_STA_ASSOC)
        return;
    
    if (mbuf_len(m) < sizeof(*psp)) {
        DPRINTF(("frame too short, len %u\n", mbuf_len(m)));
        ic->ic_stats.is_rx_tooshort++;
        return;
    }
    psp = mtod(m, struct ieee80211_frame_pspoll *);
    if (!IEEE80211_ADDR_EQ(psp->i_bssid, ic->ic_bss->ni_bssid)) {
        DPRINTF(("discard pspoll frame to BSS %s\n",
                 ether_sprintf(psp->i_bssid)));
        ic->ic_stats.is_rx_wrongbss++;
        return;
    }
    aid = letoh16(*(u_int16_t *)psp->i_aid);
    if (aid != ni->ni_associd) {
        DPRINTF(("invalid pspoll aid %x from %s\n", aid,
                 ether_sprintf(psp->i_ta)));
        return;
    }
    
    /* take the first queued frame and put it out.. */
    m = mq_dequeue(&ni->ni_savedq);
    if (m == NULL)
        return;
    if (mq_empty(&ni->ni_savedq)) {
        /* last queued frame, turn off the TIM bit */
        (*ic->ic_set_tim)(ic, ni->ni_associd, 0);
    } else {
        /* more queued frames, set the more data bit */
        wh = mtod(m, struct ieee80211_frame *);
        wh->i_fc[1] |= IEEE80211_FC1_MORE_DATA;
    }
    mq_enqueue(&ic->ic_pwrsaveq, m);
    ifp->if_start(ifp);
}
#endif	/* IEEE80211_STA_ONLY */

/*
 * Process an incoming BlockAckReq control frame (see 7.2.1.7).
 */
void
ieee80211_recv_bar(struct ieee80211com *ic, mbuf_t m,
                   struct ieee80211_node *ni)
{
    const struct ieee80211_frame_min *wh;
    const u_int8_t *frm;
    u_int16_t ctl, ssn;
    u_int8_t tid, ntids;
    
    if (!(ni->ni_flags & IEEE80211_NODE_HT)) {
        DPRINTF(("received BlockAckReq from non-HT STA %s\n",
                 ether_sprintf(ni->ni_macaddr)));
        return;
    }
    if (mbuf_len(m) < sizeof(*wh) + 4) {
        DPRINTF(("frame too short\n"));
        return;
    }
    wh = mtod(m, struct ieee80211_frame_min *);
    frm = (const u_int8_t *)&wh[1];
    
    /* read BlockAckReq Control field */
    ctl = LE_READ_2(&frm[0]);
    tid = ctl >> 12;
    
    /* determine BlockAckReq frame variant */
    if (ctl & IEEE80211_BA_MULTI_TID) {
        /* Multi-TID BlockAckReq variant (PSMP only) */
        ntids = tid + 1;
        
        if (mbuf_len(m) < sizeof(*wh) + 2 + 4 * ntids) {
            DPRINTF(("MTBAR frame too short\n"));
            return;
        }
        frm += 2;    /* skip BlockAckReq Control field */
        while (ntids-- > 0) {
            /* read MTBAR Information field */
            tid = LE_READ_2(&frm[0]) >> 12;
            ssn = LE_READ_2(&frm[2]) >> 4;
            ieee80211_bar_tid(ic, ni, tid, ssn);
            frm += 4;
        }
    } else {
        /* Basic or Compressed BlockAckReq variants */
        ssn = LE_READ_2(&frm[2]) >> 4;
        ieee80211_bar_tid(ic, ni, tid, ssn);
    }
}

/*
 * Process a BlockAckReq for a specific TID (see 9.10.7.6.3).
 * This is the common back-end for all BlockAckReq frame variants.
 */
void
ieee80211_bar_tid(struct ieee80211com *ic, struct ieee80211_node *ni,
                  u_int8_t tid, u_int16_t ssn)
{
    struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid];
    
    /* check if we have a Block Ack agreement for RA/TID */
    if (ba->ba_state != IEEE80211_BA_AGREED) {
        /* XXX not sure in PBAC case */
        /* send a DELBA with reason code UNKNOWN-BA */
        IEEE80211_SEND_ACTION(ic, ni, IEEE80211_CATEG_BA,
                              IEEE80211_ACTION_DELBA,
                              IEEE80211_REASON_SETUP_REQUIRED << 16 | tid);
        return;
    }
    /* check if it is a Protected Block Ack agreement */
    if ((ni->ni_flags & IEEE80211_NODE_MFP) &&
        (ni->ni_rsncaps & IEEE80211_RSNCAP_PBAC)) {
        /* ADDBA Requests must be used in PBAC case */
        if (SEQ_LT(ssn, ba->ba_winstart) ||
            SEQ_LT(ba->ba_winend, ssn))
            ic->ic_stats.is_pbac_errs++;
        return;    /* PBAC, do not move window */
    }
    /* reset Block Ack inactivity timer */
    if (ba->ba_timeout_val != 0)
        timeout_add_usec(&ba->ba_to, ba->ba_timeout_val);
    
    if (SEQ_LT(ba->ba_winstart, ssn)) {
        struct mbuf_list ml = MBUF_LIST_INITIALIZER();
        ieee80211_ba_move_window(ic, ni, tid, ssn, &ml);
        if_input(&ic->ic_if, &ml);
    }
}
